The vast majority of Rhododendrons prefer well drained acidic soil with a PH between 4.5 and 6 with ample organic matter. Rhodos prefer their roots cool and benefit greatly from a deep organic mulch to retain the moisture an prevent the growth of weeds without mechanical damage to the shallow roots.
If in areas where alkaline soil is the norm; Rhododendrons can always be grown in raised beds using a mixture of topsoil and peat moss. In much of the eastern U.S. the soil is acidic but soil testing can is easily done to make sure.
Rhododendrons planted on limey alkaline soil are generally chlorotic meaning undersized yellowing leaves and loss of vigor.
Most Rhododendrons with large foliage prefer partial to full shade however there are exceptions which are noted in the text beneath including some which prefer full sun.
Generally it is a safe bet to expect Rhodos to thrive in a woodland understory where they enjoy protection from wind, late frosts and hot summer sun. Rhododendrons co-exist well with Oaks however shallow rooted Maples may be too much competition for most Rhodos.
All Rhododendrons suffer from prolonged periods of 100+ F in full sun.
All Rhododendrons prefer daytime temperatures under 80 F though many can tolerate more. During excessively hot weather the plants can be sprayed with water to cool the foliage however generally this is a practice I discourage generally in horticulture due that it can increase foliar funguses that are already present.
Generally Rhododendrons that are native to the Himalayas and high mountains in western China and northeast Burma; thrive in the Pacific Northwest and western Europe, especially in the British Isles. Rhododendrons native to eastern China, Japan, Korea, eastern Siberia, eastern Europe, the Caucasus and eastern North America; are more likely to thrive the more hotter humid summers of eastern North America.
Rhododendrons are generally not bothered by insect pests however in the case that they do get attacked by thrips, mites and vine weevils, they can be treated by a systemic insecticide.
Diseases aren't generally a problem when grown in ideal conditions however root rot can be a problem on soil that isn't properly drained. Planting too deeply will result in yellow foliage and often the smothering and death of the plant.
Rhododendrons can be fed with slow release fertilizer during spring to improve vigor.
Alkaline fertilizers such as blood, fish and bone meal should be avoided.
Rhododendrons should also not be fed with fast acting high nitrogen fertilizers. They are sensitive to high levels of fertilizer salts, causing "fertilizer burn" on overfed plants.
Most prunings dislike excessive pruning so pruning should be kept to shortening over extended branches, dead and diseased wood. Pruning is best done in spring. Old spent flower clusters can also be cut off to redirect the plants energy into foliage production and more growth.
Semi-ripe cuttings and layering during mid summer are the typical methods of propagation. When available, seed works too, though you will definately have more variability with the plants that result.Cuttings taken in mid summer during early morning and should be 3 to 4 inches in length with 3 to 4 leaves retained ( cut larger leaves in half to prevent excess transpiration ).
Seeds should be grown from flowers that are hand pollinated to make sure they turn out "pure bred". They can be sown in pans containing well drained, moist peat and bottom heat from 65 to 70 F. Germination is usually around 10 to 20 days.
* photo taken on May 18 2011 in Columbia, MD
* photos taken on May 10 2012 in Columbia, MD
* photos taken on May 1 2012 in Columbia, MD
* photos taken on May 7 2014 @ London Town Gardens, Edgewater, MD
* photos taken on May 15 2014 in Columbia, MD
* photos taken on May 20 2015 in Columbia, MD
* photos taken on May 9 2019 in Columbia, MD
* historic archive photos
* photos taken on May 11 2021 in Columbia, MD
HYBRID RHODOS
Rhododendron 'Abbeys Re-view'
Fast growing, reaching up to 8 x 8 feet.
The foliage resembles that of PJM Rhododendron.
The violet-purple flowers are also similar to that of PJM Rhododendron but appear during early spring then again during autumn.
Hardy zones 5 to 8, it is both disease resistant and very heat tolerant for a Rhododendron.
* photos taken on Aug 1 2017 in Columbia, MD
* photos taken on May 1 2018 in Columbia, MD
* photos taken on Apr 18 2019 in Columbia, MD
* photos taken on Apr 13 2020 in Columbia, MD
* photo taken on Apr 23 2020 in Columbia, MD
* photos taken on July 16 2022 in Columbia, MD
* photos taken on Apr 13 2023 in Columbia, MD
* photos taken on June 24 2023 in Columbia, MD
* photos taken on Apr 16 2024 in Columbia, MD
Rhododendron 'Admiral Piet Hein'
A medium-size evergreen shrub, reaching a maximum height of 5 feet.
The leaves are glossy green.
The fragrant, rosy-lilac, funnel-shaped flowers are borne in trusses during mid spring.
Hardy zones 4 to 8. Tolerant of wind and full sun. Not generally prone to insects.
Rhododendron 'Aglo'
A dense, compact, fast growing, medium-size evergreen shrub. It is a hybrid of R. carolinianum and R. minus. Some records include: 5 years - 4 x 3 feet; 10 years - 5 x 4 feet; largest on record - 7 x 8 feet.
The aromatic, oval leaves are up to 2.2 inches in length. The glossy bright green foliage turns deep red during autumn then to bronze during winter.
The intense, pure mid pink, funnel-shaped flowers, up to 1.5 inches across, are borne in trusses over a 2 week period during early spring. The blooms appear a week after the very similar Rhodo 'PJM'.
Hardy zones 4 to 8 tolerating as low as -25 F. Tolerant of full sun.
* photo taken on April 10 2010 in Howard County, MD
* photo taken on Oct 14 2015 in Columbia, MD
* photo taken on Apr 10 2018 in Columbia, MD
* photo taken on Aug 10 2017 in Columbia, MD
* photos taken on Mar 29 2020 in Columbia, MD
* photos taken on Apr 16 2020 in Columbia, MD
* photos taken on June 18 2020 in Columbia, MD
* photos taken on May 17 2021 in Columbia, MD
* photos taken on Feb 16 2021 in Columbia, MD
* photos taken on Apr 16 2022 in Columbia, MD
* photos taken on May 16 2022 in Columbia, MD
* photo taken on July 20 2022 in Columbia, MD
Rhododendron 'Albatross'
A spreading, evergreen, large shrub to small tree that is the hybrid between R. 'Loderi' & R. fortunei 'Discolor'. Some records include: 10 years - 6+ feet; largest on record - 20 feet.
The long leaves, up to 8 inches in length, are mid-green.
The leaves generally persist for a year.
The fragrant, white ( with pink flushing ), funnel-shaped flowers, up to 4.5 inches across, are borne in trusses of 12 to 21, during late spring.
Hardy zones 6 to 8 preferring a woodland environment.
Rhododendron 'Alice'
A Rhodo. griffithianum hybrid forming a vigorous, bushy, dense, upright, medium-sized evergreen shrub. Some records include: 10 years - 6 feet; 25 years - 15 feet; largest on record - 15 feet.
The pointed leaves, up to 6 x 2 inches, are deep green.
The mid pink, broad funnel-shaped flowers, up to 4 inches across, are borne in large, pyramidal trusses of 14 to 18 during mid spring.
Hardy zones 6b to 8. Sun tolerant, tough and easy to grow. Regular pruning helps to keep it bushy.
Rhododendron 'Alison Johnstone'
A attractive, bushy, dense, medium-size, evergreen large shrub that is the hybrid between Rhodo. yunnanense x R. concatenans. Some records include: 10 years - 4 feet; largest on record - 6.5 x 6 feet.
The leaves, up to 3 inches in length, are waxy blue-green above, pale gray-blue benath.
The light orangish-pink, funnel-shaped flowers, up to 1.5 inches across, are borne in loose trusses of 9 to 10 during early to mid spring. The flowers are pink in bud.
Hardy zones 5 to 9. It prefers a woodland environment with shaded cool roots and protection from excessive wind.
Rhododendron 'America'
A spreading, low growing, medium-size, evergreen shrub. Some records include: 10 years - 5 feet.
The leaves are olive-green. In colder climates much of the foliage may fall off during late autumn, but not before turning intense orange and scarlet.
The intense scarlet-red, funnel-shaped flowers are borne in trusses of 10 to 12, during late spring.
Hardy zones 4 to 8, a R. catawbiense hybrid, it is among the most cold hardy of all red flowering Rhododendrons.
Tolerant of wind.
Rhododendron 'Angelo'
An evergreen small tree that is the hybrid between Rhodo. fortunei ssp discolor x griffithianum. Some records include: 10 years - 10 feet; largest on record - 20+ feet.
The large leaves are deep green.
The huge white to blush-pink, funnel-shaped flowers are borne in spectacular trusses during late spring.
Hardy zones 6, preferring a sheltered woodland environment.
Rhododendron 'Anah Kruschke'
A very dense, bushy, medium-size evergreen shrub that is a hybrid between Rhodo. ponticum x Purple Splendour. Some records include: 10 years - 6 x 6 feet; largest on record - 10 x 10 feet.
The attractive leaves, up to 5 inches in length, are glossy very deep green. The leaves persist up to 3 years.
The reddish-purple, funnel-shaped flowers, up to 3 x 3 inches, are borne in dense pyramidal trusses of 10 to 12 during late spring.
Hardy zones 5 to 9. It is easy to grow and even thrives with heat and sun.
* photos taken on May 20 2014 in Columbia, MD
* photos taken on May 17 2017 in Columbia, MD
* photos taken on June 1 2021 in Columbia, MD
'Anna Rose Whitney'
The hybrid between Rhodo. giersonianum × R. ‘Countess of Derby’ forming a vigorous, medium-sized evergreen shrub. Some records include: 10 years - 6.5 feet. It could possibly reach a maximum size of 20 x 20 feet.
The attractive leaves, up to 8 x 3.2 inches, are olive-green.
The impressive, deep rose-pink ( spotted light-brown ), funnel-shaped flowers, up to 4 inches wide, are borne in trusses of 12 to 21 during late spring.
Hardy zones 7 to 9 tolerating as low as -5 F
* photos taken on May 6 2010 @ Brookside Gardens, Wheaton, MD
Rhododendron 'April Glow'
A small, evergreen shrub, reaching up to 5 x 5 feet, that is the hybrid between Rhodo. williamsianum x R. Wilgen's Ruby. Some records include: 10 years - 3 x 4 feet.
The oblong leavesl up to 2.3 x 1.6 inches, are orangish-red at first, turning to deep green.
The mid-pink, funnel-shaped flowers are borne in trusses ( up to 3.7 inches across ) of 7 to 10 blooms during early spring. The flowers are deep rose-pink in bud.
Hardy zones 6 to 8 ( tolerating -10 F ).
Rhododendron 'April Rose'
An upright to domed shrub, reaching up to 4 x 4 feet. It is a hybrid between Rhododendron 'Cornell Pink' and R. dauricum.
The elliptical leaves are deep green, turning to bronze-red during autumn.
The purplish-red, double flowers, up to 2 inches wide, appear during early or mid spring.
Hardy zones 5 to 8 ( tolerating -25 F ) in full sun to partial shade.
* photo taken on July 26 2015 @ Niagara Parks Bot. Gardens, Niagara Falls, ON
Rhododendron 'Arctic Snow'
A dense, upright shrub, reaching up to 4 feet in 10 years, that is that hybrid between R. brachycarpum & R. maximum.
The double flowers are light pink in bud, opening to pure white ( sprinkled with bright yellow spots ).
Hardy zones 5 to 8 ( tolerating as low as -25 F ).
Rhododendron 'Arthur Bedford'
A Rhodo. ponticum hybrid, forming a vigorous, upright, large evergreen shrub. Some records include: 10 years - 10 x 10 feet.
The elliptical leaves, up to 6.5 inches in length, are glossy deep green. The leafstalks are red.
The lavender flowers ( blotched deep brownish-red ), funnel-shaped flowers, up to 3.5 inches across, are borne in dome-shaped trusses of 11 to 16 during late spring.
Hardy zones 4 to 8. Heat and sun tolerant.
* photo taken on May 6 2010 @ Brookside Gardens, Wheaton, MD
Rhododendron 'Arthur J 'Ivens'
The hybrid between R. fortunei × R. williamsianum, forming a domed, medium-size evergreen shrub. Some records include: 10 years - 4 feet.
The ovate leaves, up to 2.7 x 1.5 inches, are green.
The rose-pink, bell-shaped flowers, up to 3.3 inches across, are borne in trusses of 4 or 5, during late spring.
Hardy zones 4 to 8
Rhododendron 'Arthur Osburn'
The hybrid between Rhodo. sanguineum ssp didymum x R. griersonianum, forming a very attractive, compact, spreading, medium-size evergreen shrub. Some records include: 10 years - 5 feet.
The large leaves are gray-green above, fawn-brown woolly beneath.
The very deep red, funnel-shaped flowers are borne in trusses during early summer.
Hardy zones 6 to 8. May be prone to Powdery Mildew.
Rhododendron 'Astarte'
A low bushy evergreen shrub, reaching up to 4 feet in 10 years.
The leaves are green.
The apricot-orange, pendulous, funnel-shaped flowers are borne in trusses of 8 during mid spring.
Hardy zones 5 to 9
Rhododendron 'Auguste van Geert'
A vigorous, medium-sized evergreen shrub, reaching a height of 6+ feet.
The leaves, are green.
The abundant, large, red-purple,funnel-shaped flowers are borne in trusses during early spring.
Hardy zones 5 to 9 tolerating sun and even windy sites.
Rhododendron 'Award'
A medium-size evergreen shrub, reaching a maximum height of 6 feet. Some records include: 10 years - 5 x 5 feet.
The long narrow oblong leaves, up to 7.5 inches in length, are greenish-bronze, turning to matte green. The foliage persists for 2 years.
The fragrant, white ( flared yellow ), funnel-shaped flowers, up to 4.5 inches across, are borne in rounded trusses of 14 or 15 during mid spring. The margins of the flowers are shaded pink.
Hardy zones 7 to 9
Rhododendron 'Babylon'
The hybrid between R. calophytum X R. praevernum. A dense, rounded large evergreen shrub. Some records include: 10 years - 10 x 6 feet.
The very long leaves are glossy deep green.
The huge, striking white ( with deep red blotch ) funnel-shaped flowers, up to 5 inchs across, are borne in huge, dense, rounded trusses during early spring.
The strong, rigid stems are red.
Hardy zones 5 to 8
Rhododendron 'Baden Baden'
A dense, spreading, medium-sized evergreen shrub that is the hybrid between Rhodo. forrestii ssp forrestii and R. 'Essex Scarlet'. Some records include: 10 years - 2 x 2 feet; largest on record - 3 x 6 feet.
The wavy, broadly-ovate leaves, up to 3.5 inches in length, are very glossy deep green.
The glowing red, funnel-shaped flowers, up to 2.5 inches across, are borne in trusses of up to 6, during late spring.
Hardy zones 5b to 8, tolerating as low as -15 F. It does not enjoy hot humid summers but does well in the Pacific Northwest and some of the more maritime parts of the northeast.
* photo taken on Oct 1 2016 in Annapolis, MD
Rhododendron 'Beauty of Littleworth'
A hybrid containing Rhodo. campanulatum x R. griffithianum; forming a very fast growing, sturdy, leggy, upright to spreading, evergreen small tree. Some records include: 10 years - 6 feet; largest on record - 17 x 13 feet.
The elliptical leaves, up to 8 x 4 inches, are glossy deep green above, bronze beneath.
The fragrant, pure white ( with reddish-purple speckles ) funnel-shaped flowers, up to 5 inches across, are borne in huge trusses of 16 to 19 during mid-spring.
Hardy zones 6b to 8 ( tolerating -5 F ) preferring a site protected from excessive wind.
Rhododendron 'Besse Howells'
Dense and spreading in habit, it is a hybrid between Rhodo. catawbiense & R. 'Boule de Neige'. It reaches only 3 x 3 feet in 10 years, with an eventual maximum size of 4 x 6 feet.
The leaves, up to 4 inches in length, are deep green.
The very abundant, reddish-purple flowers, up to 2.5 inches wide, are borne on rounded clusters during early summer.
Hardy north to zone 5a ( -20 F ).
* photos taken on May 16 2014 in Columbia, MD
* photo taken on July 13 2014 in Columbia, MD
* photo taken on May 13 2015 in Columbia, MD
* photo taken on June 9 2016 in Columbia, MD
* photos taken on May 2 2016 in Columbia, MD
* photo taken on May 2 2017 in Columbia, MD
* photo taken on May 9 2019 in Columbia, MD
Rhododendron 'Betty Wormald'
An compact, upright to spreading, large evergreen shrub, reaching a maximum size of 12 x 10 feet. Some records include: 10 years - 10 feet.
The large oblong leaves, up to 7 x 2.5 inches, are very deep, glossy green.
The very large, light pink, ( paler centered and spotted light purple ), funnel-shaped flowers, up to 4 inches across, are borne on massive, domed trusses of 10 to 12, during late spring.
Hardy zones 4 to 8
Rhododendron 'Bibiani'
The hybrid between Rhodo. arboreum x R. Moser's Maroon forms a vigorous, upright, medium-sized evergreen shrub. Some records include: 10 years - 10 x 6 feet; largest on record - 15 x 15 feet. Makes an excellent informal hedge due to its dense foliage.
The elliptic leaves, up to 6 x 2 inches, are glossy deep green, silvery to brown beneath. The leaves persist up to 4 years.
The abundant, intense red, bell-shaped flowers, up to 2.5 inches across, are borne in dense globular trusses of 14 during early spring,
Hardy zones 7b to 9 ( tolerates 5 F ) prefers partial shade and protection from wind. Easy to grow from cuttings. Heat tolerant.
Rhododendron 'Blue Baron'
A very dense, compact, upright, small evergreen shrub. Some records include: 10 years - 3 x 2 feet; largest on record - 6 x 4 feet.
The small, oblong leaves, up to 2 inches in length, are glossy mid-green, turning to bronze during winter.
The very abundant, deep purple-blue, funnel-shaped flowers, up to 1.3 inches across, are borne in domed trusses of up to 20, during late spring into early summer.
Hardy zones 5 to 8 ( tolerating -20 F ).
Rhododendron 'Bluebird'
A dense, small, evergreen shrub that is a hybrid between R. augustinii & R. intricatum. Some records include: 10 years - 3 x 6 feet; largest on record - 4 x 8 feet.
The small leaves are green.
The abundant, rich violet-blue, funnel-shaped flowers, up to 2 inches wide, are borne in small trusses during early spring.
Hardy zones 6
Rhododendron 'Blue Crown'
A compact, small evergreen shrub, reaching a maximum height of 6 feet.
The elliptical leaves are deep green above, silvery-white beneath.
The violet ( lighter centered with magenta blotch ), funnel-shaped flowers are borne in trusses of 20 during mid to late spring.
Hardy zones 4 to 8
Rhododendron 'Blue Diamond'
A cultivar of R. augustinii. A moderate growing, dense, compact, medium-size, evergreen shrub that is the hybrid augustinii. Some records include: 10 years - 4 x 4 feet; 18 years - 7 feet; largest on record - 11 x 5 feet.
The small, elliptical leaves, up to 1.5 x 0.6 inches, are deep green, turning to bronze in winter.
The abundant, light blue, funnel-shaped flowers, up to 1.7 x 2 inches, are borne in trusses of 4 to 5 during early to mid spring.
Hardy zones 6 to 8. Likes sun.
Rhododendron 'Blue Nose'
Reaching up to 4 feet in 10 years, this is the Ontario, Canada developed cold hardy hybrid between R. augustinii & R. dauricum.
The flowers are violet-blue.
Hardy zones 5a to 8 ( tolerating as low as -25 F ).
Rhododendron 'Blue Peter'
A Rhodo. ponticum hybrid, forming a vigorous, compact, bushy, medium-size, evergreen shrub. Some records include: fastest recorded growth rate - 1.5 feet; 10 years - 10 x 6 feet; largest on record - 10 x 17.5 feet.
The long, elliptical leaves, up to 7 inches in length, are glossy deep green.
The blue-violet ( with a paler center as well as a purple flare ), frilled, funnel-shaped flowers, up to 2.8 inches across, are borne in tight, pyramidal trusses of up to 15, during late spring. The flowers have a large purple blotch and the petal edges are very frilly.
Hardy zones 4 to 8 in sun or shade. Tolerant of heat and sun. Easy to grow from cuttings.
* photos taken on May 10 2014 in Columbia, MD
Rhododendron 'Blue Ridge'
The hybrid between R. russautinii & R. augustinii, forming a vase-shaped, compact, medium-sized evergreen shrub. Some records include: 10 years - 4 x 4 feet.
The leaves are deep green. The foliage droops during winter and perks up in spring.
The intense, bright-blue, funnel-shaped flowers are borne in trusses during mid-spring.
Hardy zones 5 to 8
Rhododendron 'Blue Tit'
A mounding, dense, very compact, small, evergreen shrub that is the hybrid between Rhodo. angustinii & R. impeditum. Some records include: 10 years - 2.5 feet; 15 years - 4 x 6 feet ( rarely over 3 feet in height ).
The small, elliptical to rounded leaves, up to 1 inch in length, are bright yellowish-green at first, turning to dull mid to deep-green.
The very abundant, lavender-blue, broad funnel-shaped flowers, up to 1.5 inches across, are borne in trusses of 3 to 5 during mid spring.
Hardy zones 4 to 8 in sun to partial shade, preferring a site sheltered from excessive wind. Prone to chlorosis on alkaline soil.
Rhododendron 'Boddeartianum'
The hybrid between Rhodo. arboreum x R. campanulatum, forming a bushy, compact, evergreen large shrub. Some records include: 10 years - 10 feet; largest on record - 27 feet with a trunk diameter of 15 inches.
The narrow ellitpical leaves, up to 7 x 1.5 inches, are mid-green.
The white ( with deep red ray and a deep purple blotch ), funnel-shaped flowers are borne in dense, globular trusses of 18 to 22 during mid spring.
Hardy zones 5 to 9.
Rhododendron 'Boule de Neige'
The hybrid between R. caucasicum & R. catawbiensis, forming a vigorous, dense, rounded, medium-size, evergreen shrub. Some records include: fastest recorded growth rate - 2 feet; 10 years - 5 x 5 feet; largest on record - 10 x 10 feet.
The leathery, obovate leaves, up to 4.3 x 2 inches, are deep matte green.
The pure white, broad funnel-shaped flowers, up to 2.4 inches across, are borne in rounded trusses of up to 10 during late spring.
Hardy zones 4 to 7. Sun and heat tolerant. Easy to grow.
Rhododendron 'Bow Bells'
The hybrid between Rhodo. 'Corona' x R. williamsianum, forming a dense, rounded, medium-size evergreen shrub. Some records include: 10 years - 5 feet; largest on record - 7 x 8 feet.
The ovate leaves, up to 3 inches in length, are shiny red-orange at first, turning to deep green.
The abundant, light pink, cupped flowers, up to 2.5 x 2.3 inches, are borne in loose trusses of 4 to 7 during mid spring. The flowers are deep pink in bud.
Hardy zones 6b to 8 ( tolerates -5 F ). Prefers light to medium shade, it does not like direct sun.
Rhododendron 'Bric a Brac'
The hybrid between R. leucapis & R. moupinense, forming a very attractive, somewhat open, spreading, low growing evergreen shrub. Some records include: 10 years - 3.3 feet; largest on record - 3.3 x 5 + feet.
The small, fuzzy, obovate or elliptical leaves are up to 2 inches in length. The foliage is bronze at first, turning to downy glossy deep green above, bright green beneath.
The small, pure white ( with brown anthers ), broad funnel-shaped flowers, up to 2 inches across, are borne in lax trusses of 3 during very early spring.
Older stems have shiny, peeling, papery bark.
Hardy zones 5 to 9 preferring a site protected from excessive wind.
Rhododendron 'Brittania'
A dense, rounded, small, evergreen shrub, reaching a maximum size of 10 x 8.5 feet. Some records include: 10 years - 6 x 6 feet.
The deeply-veined, obovate leaves, up to 9 inches in length, are bright green. The leaves last for up to 3 years.
The scarlet-red, funnel-shaped flowers, up to 2.7 inches across, are borne in domed trusses of up to 15 during late spring.
Hardy zones 5b to 8
Rhododendron 'Broughtonii'
A hybrid of Rhodo. arboreum, forming a vigorous, bushy, dense, small evergreen tree. Some records include: 10 years - 20 feet; largest on record - 30+ feet.
The leathery leaves, up to 10 x 3 inches, are deep green. Foliage may yellow a bit in full sun.
The rosy-red ( spotted darker ), funnel-shaped flowers, up to 3.5 inches across, are borne in large, conical trusses of 20 during early to mid spring.
Hardy zones 7 to 8
Rhododendron 'Calsap'
A vigorous, dense, upright, medium-size evergreen shrub, reaching a maximum size of 10 x 10 feet. Some records include: 10 years - 6 x 5 feet.
The oblong leaves, up to 5.5 inches in length, are smooth, verdant, mid-green. The leaves persist up to 2 years.
The white ( boldly blotched deep-red ), funnel-shaped flowers, up to 2.7 inches across, are borne in conical trusses of up to 18 during late spring. The flowers are lavender in bud.
Hardy zones 4 to 8. It is a prolific seeder and should be deadheaded for improved vigor.
Rhododendron 'Canary'
The hybrid between R.campylocarpus & R.caucasicum, forming a dome-shaped, medium-size evergreen shrub. Some records include: 10 years - 4 feet.
The deeply-veined, crinkly leaves are bright green.
The bright yellow, funnel-shaped flowers are borne in tight trusses during mid spring.
Hardy zones 4 to 8
Rhododendron 'Capistrano'
A compact, dense, domed, spreading, medium-sized evergreen shrub. Some records include: 10 years - 6 x 7 feet; largest on record - 7 x 8 feet.
The elliptical leaves, up to 4.5 inches in length, are dull deep green.
The light yellow ( with no markings ), frilled, funnel-shaped flowers, up to 2 inches across, are borne in domed trusses, up to 8 inches across, consisting of up to 15, during early summer.
Hardy zones 5 to 8, tolerating -20 F, preferring afternoon shade. Not generally prone to disease but requires excellent drainage.
* photo taken on May 14 2011 in Columbia, MD
* photos taken on Apr 27 2015 in Elkridge, MD
Rhododendron 'Carita'
The hybrid between R. campylocarpum & R. 'Naomi' forming a handsome, large evergreen shrub. Some records include: 10 years - 10 x 6.5 feet; largest on record - 18 x 10 feet.
The leaves, up to 6 x 3 inches, are rich-green. The foliage typically persists for slightly over a year.
The light yellow, funnel-shaped flowers, up to 3.5 inches in length. The flowers are deep pink in bud.
Hardy zones 5 to 9.
Rhododendron 'Carmen'
The hybrid between Rhodo. sanguineum ssp didymum x R. forrestii Repens forming a sturdy, dense, low, spreading evergreen shrub. Some records include: 10 years - 2 x 2.5 feet; largest on record - 2 x 4 feet.
The rounded leaves, up to 1.7 inches in length, are glossy, verdant, mid-green.
The intense scarlet-red, bell-shaped flowers, up to 1.3 inches across, are borne in trusses of 2 to 5 during early to mid spring.
Hardy zones 7 to 8 ( hardier with reliable snow cover ). Tolerant of full sun.
Rhododendron 'Caronella'
The hybrid between R. caroliniana & R. mucronulatum 'Cornell Pink' forming a fast growing, upright, medium-sized evergreen shrub that resembles Rhodo. 'PJM'. Some records include: 8 years - 5 x 2.5 feet; largest on record - 12 x 12 feet.
The long oval leaves, up to 3 inches in length, are glossy deep green with about 1/3 retained over the winter and the remainder turning orange-red before dropping in autumn.
The light purplish-pink ( with darker fringes ), broad funnel-shaped flowers, up to 1.5 inches across, are borne in domed trusses of 6 during late spring.
Hardy zones 5 to 8
Rhododendron 'Chevalier Felix de Sauvage'
A Rhodo. caucasicum hybrid, forming a dense, compact, broadly spreading, large evergreen shrub. Some records include: 10 years - 5 feet; largest on record - 13 x 8 feet.
The elliptical leaves, up to 5 x 2 inches, are matte-green.
The abundant, mid-sized, coral-pink ( deeper blotch in center ), funnel-shaped flowers, up to 2.5 inches across, are borne in dense rounded trusses of 9 to 15 during early to mid spring.
Hardy zones 6b to 8
Rhododendron 'Chikor'
The hybrid between Rhodo. ludlowii x R. rupicola var chyseum, forming a compact, rounded, twiggy small evergreen shrub that is more closer in appearance to a miniature bonsai tree. Some records include: 10 years - 20 inches; largest on record - 5 feet.
The small, broad elliptical leaves, up to 0.7 inches in length, are glossy deep green turning to bronze-red during winter.
The soft yellow ( with darker spots ), funnel-shaped flowers, up to 1.2 inches across, are borne in trusses of 2 to 6.
Hardy zones 7 to 9 in sun or partial shade on soil that is acidic to neutral.
Rhododendron 'Chink'
The hybrid between Rhodo. trichocladum x R. keiskei, forming a compact, upright, small, evergreen shrub, reaching a maximum height of 5 feet. Some records include: 10 years - 4 feet.
The small, elliptical leaves are bronze at first, turning to bright green. In cold climates it may become deciduous during some winters.
The light yellow, funnel-shaped flowers are borne during very early spring.
Hardy zones 6 to 8
Rhododendron 'Chionoides'
The hybrid of Rhodo. ponticum, forming a moderate growing, dense, spreading, medium-size evergreen shrub. Some records include: 10 years - 7 x 7 feet; largest on record - 12 x 12 feet.
The long, narrow, elliptical leaves are bright green, turning to deep green.
The abundant, white ( with bright yellow dorsal blotch ), funnel-shaped flowers, up to 2 inches across, are borne in domed trusses of 12 to 18 during mid spring.
Hardy zones 4 to 9. Tolerant of sun, wind and heat.
* photo taken on May 1 2010 in Howard County, MD
* photo taken on June 1 2010 in Columbia, MD
* photos taken on May 18 2011 in Columbia, MD
* photos taken on May 21 2018 in Columbia, MD
Rhododendron 'Christmas Cheer'
A Rhodo. caucasicum hybrid, forming a compact, very dense, mounding, medium-size, evergreen shrub. Some records include: 10 years - 6 x 6 feet; largest on record - 13 x 13 feet.
The narrowly-elliptical leaves, up to 4 inches in length, are deep green.
The pale-pink, broad funnel-shaped flowers, up to 2 inches across, are borne in small trusses of up to 8, during early spring, sometimes repeating during autumn. The flowers are pink in bud.
Hardy zones 4b to 9, Sun and drought tolerant.
Rhododendron 'Chrysomanicum'
A low, dense, spreading evergreen shrub, reaching up to 3.3 feet in 10 years.
The leaves are glossy deep green.
The very abundant, bright yellow, funnel-shaped flowers are borne in loose trusses of 8 during early spring.
Hardy zones 5 to 9. The flower buds are prone to damage from late spring frost.
Rhododendron 'Cilpinense'
The hybrid between R. ciliatum & R. moupinense, which forms a compact, small, evergreen shrub. Some records include: 10 years - 3 feet; largest on record - 5 x 4 feet.
The finely hairy, elliptic leaves, up to 2 inches, are glossy deep green.
The abundant, large, light pink ( with deeper pink edges ), funnel shaped flowers, up to 3 inches across, are borne in trusses of 2 to 3 during very early spring.
Hardy zones 5 to 9. Does not enjoy deep shade.
Rhododendron 'C.I.S.'
The hybrid between R. 'Loder's White' & R.'Fabia', forming a medium-size evergreen shrub. Some records include: 10 years - 4 feet; largest on record - 10 x 10 feet.
The leaves, up to inches, are green. The leaf tips are twisted.
The abundant, orangish-yellow ( throated orange-red ) funnel-shaped flowers, up to 4 inches across, are borne in loose trusses of around 11 during mid spring.
The flowers fade to creamy-orange before falling.
Hardy zones 5 to 9
Rhododendron 'Cornish Cross'
The hybrid between R. griffithianum x R. thomsonii forming an evergreen small tree. Some records include: 10 years - 20 feet.
The large leaves are bright green.
The red-pink, funnel-shaped flowers are borne in large trusses during early spring.
The attractive bark is light brown and peeling.
Hardy zones 8 to 9; thriving in the U.S. only in the Pacific Northwest. May be damaged by late spring frosts.
Rhododendron 'Cornubia'
The hybrid between R. arboreum & R.'Shilsonii' forming a very vigorous open, evergreen large shrub to small tree. Some records include: 10 years - 10 feet; largest on record - 20+ feet.
The large, elliptical to obovate leaves, up to 6 inches in length, are dull mid olive-green.
The intense deep red, funnel-shaped flowers, up to 2.5 inches across, are borne in large pyramidal trusses of up to 12 during very early spring.
Hardy zones 7 or 8 to 9. Easy to reproduce from cuttings.
Rhododendron 'Countess of Haddington'
The hybrid between R. ciliatum & R.dalhousiae, forming a compact, medium-size, evergreen shrub. Some records include: 10 years - 6.5 feet; largest on record - 7 x 8 feet.
The lance-shaped to oblong leaves, up to 4 inches in length, are bright green and scaly.
The very abundant, fragrant, white flushed with rose ( with yellow-brown markings ), funnel-shaped flowers, up to 3 inches across, are borne in loose trusses of 2 to 6 during mid spring.
The flowers are pink in bud.
Hardy zones 8 to 9, thriving in the Pacific Northwest.
Rhododendron 'County of York'
A fast growing, broad-spreading, large shrub, reaching up to 8 x 6 feet in 10 years, and an eventual maximum size of 15 feet. It is the hybrid between Rhodo. catawbiensis 'Album' & Rhodo. 'Loderi King George'.
The large leaves, up to 12 inches in length, are glossy bright green, later turning to deep green.
The large flowers, up to 4 inches across, are borne in trusses of 13. They are lavender-pink in bud, opening to white ( olive-green throat blotched ).
Hardy zones 6 to 8 ( tolerating -15 F ) in partial shade.
* photos taken on May 6 2012 in Baltimore, MD
Rhododendron 'C.P. Raffil;'
The hybrid between R. 'Brittania' & R. griersoniana, forming a dense, spreading, medium-size evergreen shrub. Some records include: 10 years - 5 feet.
The leaves, up to 6 inches in length, are bright green. The leafstalks are reddish-brown.
The deep orange-red, funnel-shaped flowers are borne in large, globular trusses of during early spring.
Hardy zones 7 to 9, may be damaged by late spring frosts.
Rhododendron 'Crater Lake'
An upright, evergreen shrub, reaching up to 6 x 5 feet in 10 years, eventually slightly more. It is a hybrid between R. augustinii 'Barto Blue' and R. 'Blue Bird'
The elliptical leaves, up to 2 inches in length, persist up to 2 years. The foliage is bronzy-yellow at first, turning to bright green.
The intense, bright violet-blue flowers, up to 2 inches wide, are borne in clusters of 3.
Hardy zones 6b to 8 in full sun.
Rhododendron 'Creamy Chiffon'
A compact, upright, medium-size evergreen shrub, reaching a maximum height of 4 feet. Some records include: 10 years - 3 feet.
The elliptical leaves, up to 3 inches in length, are glossy deep olive-green.
The leaves persist up to 3 years.
The creamy-yellow, double flowers, , up to 3 inches across, are borne in flat trusses of 7 during mid to late spring. The flowers are pinkish-orange in bud.
Hardy zones 7 to 9 ( tolerating -5 F ), 'Lemon Dream' is similar but much hardier to as far north as zone 6 ( tolerating -15 F )
Rhododendron 'Creeping Jenny'
The hybrid between R.griersonianum & R. forrestii repens, forming a compact, dense, low to creeping evergreen shrub. Some records include: 10 years - 2 feet; largest on record - 3.3 x 6.5 feet. Excellent for use in a rock garden or on a bank.
The small leaves are deep green.
The abundant, scarlet-red, bell-shaped flowers are borne in large, loose trusses of 5 to 6 during early to mid spring.
Hardy zones 5 to 9
Rhododendron 'Crest'
An open, upright, vigorous, medium-sized evergreen shrub that has Rhodo wardii in its genes. Some records include: 10 years - 6 feet; largest on record - 13 x 13 feet.
The oval to oblong leaves, up to 4.5 inches in length, are glossy deep green. The leaves are typically held for just over 1 full year.
The abundant, bright yellow ( deeper yellow throat ), funnel-shaped flowers, up to 4 inches across, are borne in large, domed trusses of 12 during mid spring.
Hardy zones 6 to 8
Rhododendron 'Crossbill'
The hybrid bwetween Rhodo. spinuliferum x R. lutescens forming a erect, slender, medium-size evergreen shrub. Some records include: 10 years - 6.5 feet.
The large, crinkled leaves are bright red, turning to green.
The abundant, small, yellow ( with orange flushing ), tubular flowers are borne in trusses of over a long season during early spring.
Hardy zones 5 to 9, protect from excessive wind.
Rhododendron 'Cunningham White'
The hybrid between R. caucasicum & R. ponticum 'Album, forming an attractive, very dense, compact, medium-sized evergreen shrub. Makes an excellent informal low hedge. Some records include: 10 years - 6 x 5 feet; largest on record - 13 x 15 feet.
The oblanceolate leaves, up to 6 x 2 inches, are glossy deep green.
The abundant, white ( with greenish-yellow blotch ), funnel-shaped flowers, up to 2.4 inches across, are borne in lax trusses of up to 8 during mid to late spring, often repeating during autumn.
Hardy zones 6 to 8 tolerating as low as -15 F. Alkaline, wind and pollution tolerant. Easy to grow from cuttings.
* photos taken on Apr 15 2013 in Columbia, MD
* photos taken on Apr 26 2013 in Columbia, MD
* photo taken on July 8 2014 in Columbia, MD
* photos taken on June 29 2016 in Columbia, MD
* photo taken on Apr 20 2017 in Columbia, MD
* historic archive photos
* photos taken on May 8 2017 in Columbia, MD
* photos taken on May 6 2021 in Columbia, MD
Rhododendron 'Curlew'
The hybrid between Rhodo. ludlowii x R. fletcherianum, forming a spreading, compact, small evergreen shrub. Some records include: 10 years - 2 feet; largest on record - 2 x 3.3 feet.
The tiny, oval to rounded leaves are glossy mid green. The leaves persist up to 2 years.
The abundant, large, bright yellow ( with greenish-brown markings ), broad funnel-shaped flowers, up to 2 inches across, are borne in compact trusses of 1 to 3 during late spring.
Hardy zones 6 to 9 in partial shade on well drained soil. Do not fertilize.
Rhododendron 'Cynthia'
The hybrid between R. catawbiensis & R. griffithianum. A very vigorous, strong growing, bushy, domed, evergreen large shrub. Some records include: 10 years - 6 feet; largest on record - 33 x 23 feet.
The oblong leaves, up to 7 x 3 inches, are deep green. The foliage droops during the winter.
The abundant, showy, intense deep rose-red ( with blackish markings ), funnel-shaped flowers, up to 3.3 inches across, are borne in large pyramidal trusses of up to 24 during mid spring.
Hardy zones 5 to 8, tolerating as low as -15 F. Tolerant of sun and shade as well as heat. Rarely prone to pests.
Rhododendron 'David'
A compact, medium-sized, evergreen shrub, reaching a maximum size of 6 x 10 feet.
The elliptical leaves, up to 7 inches in length, are deep green with a yellow center midrib.
The deep red, bell-shaped flowers are borne in loose rounded trusses during early to mid spring. The flowers have frilly margins and white anthers.
Hardy zones 5 to 9 in full sun to partial shade.
Rhododendron 'Dora Amateis'
The hybrid between R. caroliniana & R. ciliatum, forming a moderate growing, low, dense, bushy, small evergreen shrub. Some records include: 10 years - 3 x 6 feet; largest on record - 5 x 8 feet.
The leaves, up to 5 ( usually under 3 ) inches, are glossy deep green to bronze-green ( if grown in full sun ).
The very abundant, fragrant, pure white ( lightly spotted green ), broad funnel-shaped flowers, up to 2 inches across, are borne in loose trusses of 3 to 8 during early to mid spring.
Hardy zones 4 to 8 in full sun to partial shade.
* photos taken by Milan Havlis, owner of central Europe's premier plant nursery
Rhododendron 'Earl of Athlone'
A medium-size, evergreen large shrub, reaching a maximum size of 17 x 13 feet.
The leaves are green.
The intense-red, funnel-shaped flowers are borne in trusses during spring.
Hardy zones 5. Prefers protection from excessive wind.
Rhododendron 'Edith Bosley'
The hybrid of unknown parentage other than it does contain Rhodo. 'Lee's Dark Purple'. It forms a moderate growing, upright, dense medium-sized evergreen shrub. Some records include: 10 years - 5 x 5 feet; largest on record - 6 x 6 feet.
The long, elliptical leaves, up to 3.7 inches in length, are deep olive-green.
The leaves persist up to 3 years.
The intense deep violet-purple ( with deep red spot ), broad funnel-shaped flowers, up to 3 inches across, are borne in large trusses during late spring.
Hardy zones 4 to 8
Rhododendron 'Eldorado'
An open, low evergreen shrub, reaching a maximum height of 4 feet.
The small leaves are scaly, deep yellow-green.
The light yellow, funnel-shaped flowers are borne in loose trusses of 3 to 4 during mid spring.
Hardy zones 6 to 9
Rhododendron 'Elizabeth'
The hybrid between R. forrestii repens & R. griersonianum, forming a vigorous, compact, dense, domed, medium-sized, evergreen shrub. Some records include: 10 years - 5 feet; 18 years - 5 x 10 feet; largest on record - 13+ x 12 feet.
The narrow oblong leaves, up to 5 x 1.3 inches, are rich, glossy, deep green. The foliage often persists for 3 years.
The very abundant, large, scarlet-red, funnel-shaped flowers, up to 4 inches across, are borne in loose trusses of 6 to 9 during early to mid spring, often lightly repeating during autumn.
Hardy zones 7 to 9 tolerating as low as 0 F, in sun to partial shade.
Rhododendron 'Elizabeth Golden variagated form'
Very attractive during all seasons!!! with deep green foliage edged in yellow. Otherwise similar to Rhodo. 'Elizabeth'.
Rhododendron 'Elizabeth Red'
Similar to 'Elizabeth' with very attractive burgundy-red new foliage.
Rhododendron 'Else Frye'
A Rhodo. ciliatum hybrid, forming a medium-size evergreen shrub. Some records include: 10 years - 4 feet; largest on record - 8 feet.
The deeply veined, leathery, elliptical leaves are bronze-green turning to glossy deep green above, light blue-green and scaly beneath. The leaves and stems are densely covered in brown hairs.
The very fragrant, white flushed pink ( with yellow throat ), broad funnel-shaped flowers, up to 4 inches across, are borne in trusses of 3 to 6 during early to mid spring.
The bark is reddish-brown.
Hardy zones 8 to 10
Rhododendron 'Elviira'
A dense, very low growing, evergreen shrub that is the hybrid between Rhodod. brachycarpum subsp tigerstedtii & R. forrestii 'Repens'. Some records include: 10 years - 2 x 4 feet; largest on record - 4 x 4 feet.
The oblong leaves, up to 2.4 inches in length, are glossy green and frequently tinged red.
The abundant, scarlet-red, funnel-shaped flowers, are borne in trusses during spring.
Hardy zones 4 to 8, bud hardy to -29 F
Rhododendron 'Everestianum'
A vigorous, medium-sized evergreen shrub. This is the hybrid between Rhodo. catawbiensis & an unknown. Some records include: 10 years - 10 feet.
The oblong leaves, up to 4.5 x 2 inches, are deep olive-green.
The abundant, rosy-lilac, funnel-shaped flowers, up to 2 inches across, are borne in dense, rounded trusses of around 15 during mid to late spring. The frilled edge flowers are spotted in the throat.
Hardy zones 4 to 8 in sun or light shade. Rarely bothered by pests*.
Rhododendron 'Fabia'
The hybrid between R. dichroananthum & R. griersonianum, forming a compact, domed, medium-size evergreen shrub. Some records include: 10 years - 5 feet; largest on record - 7 x 10 feet.
The elliptical to narrow oblong leaves, up to 5 inches in length, are deep green.
The scarlet-red ( shading to orange in the center ), bell-shaped flowers, up to 3 inches across, are borne in loose, hanging trusses of up to 9 during late spring.
Hardy zones 5 to 9 in partial shade.*
Rhododendron 'Fastuosum Flore Pleno'
The hybrid between R. catawbiensis & R. ponticum, forming a vigorous, dense, upright, rounded, evergreen small tree. Some records include: 10 years - 13 x 12 feet; largest on record - 20 x 18 feet.
The leaves, up to 6 x 2 inches, are matte deep green.
The double, lavender to purple-pink, funnel-shaped flowers, up to 2.7 inches across, are borne in loose trusses of 15 to 17 during mid to late spring.
Hardy zones 4 to 8. Tough and tolerant of sun.
Rhododendron 'Firebird'
The hybrid between Rhodo. griersonianum x R. 'Norman Shaw' forming a medium-sized evergreen shrub. Some records include: 10 years - 6 feet; largest on record - 13 feet.
The deeply-veined, long, elliptical leaves are bright green, turning to deep green.
The glowing, orangish-red ( with bright yellow anthers ), funnel-shaped flowers, up to inches in length, are borne in large trusses of during mid to late spring.
Hardy zones 5 to 9
Rhododendron 'Fireman Jeff'
A dense, spreading, medium-size evergreen shrub, reaching up to 4 x 6 feet. Some records include: 10 years - 3.3 x 5 feet. Excellent for use in rock gardens or on a bank.
The lance-shaped leaves, up to 3 inches in length, are mid-green, persisting for 3 years.
The intense red, broad funnel-shaped flowers, up to 2.5 inches across, are borne in compact trusses of up to 10 during mid spring.
Hardy zones 5 to 9 requiring acidic well drained soil and preferring an open sunny site.
Rhododendron 'Flora Markeeta'
A medium-size evergreen shrub. Some records include: 10 years - 4 x 5 feet.
The rounded leaves are glossy green.
The ivory white ( fringed with bright pink ) funnel-shaped flowers, are borne in globular trusses of 10 during early to mid spring. The flowers are pink in bud.
Hardy zones 4 to 8
Rhododendron 'Firestorm'
An attractive, mounded, wide-spreading shrub, reaching up to 5 x 10 feet.
The foliage is bright green, turning to deep green with a bright green midrib.
The very abundant flowers are intense scarlet-red.
Hardy zones 5 to 8 ( tolerating as low as -25 F ).
Rhododendron 'Florence Mann'
A compact, medium-size evergreen shrub, reaching a maximum height of 5 feet.
The leaves are green.
The abundant, deep lavender-blue, funnel-shaped flowers are borne in trusses of during early to mid spring.
Hardy zones 5 to 9. Heat tolerant.
Rhododendron 'Forsterianum'
The hybrid between Rhodo. veitchianum x R. edgeworthii, forming an open, upright, medium-size evergreen shrub. Some records include: 10 years - 5 feet; largest on record - 8 feet.
The lance-shaped leaves, up to 2.7 inches, are glossy deep green above, densely hairy beneath.
The very fragrant, white ( with yellow flare ), funnel-shaped flowers, up to 4 inches in length, are borne in loose trusses of 3 to 4 during mid spring.
Hardy zones 9 to 10, tolerating as low as 20 F. Requires partial shade.
Rhododendron 'Fragrantissimum'
The hybrid between R. edgeworthii & R. formosana, forming a somewhat leggy, medium-sized evergreen shrub. Some records include: 10 years - 5 feet; largest on record - 8 x 8 feet.
The hairy, heavily-veined, oblong to ovate leaves, up to 4 inches, are glossy deep green. The leaves persist up to 2 years.
The very fragrant, white tinged pink ( with creamy-yellow center ), trumpet-shaped flowers, up to 4 inches across, are borne in loose trusses of 4 during early to mid spring. The flowers are pinkish-orange in bud.
Hardy zones 8 to 9. Regular pruning helps maintain a compact habit.
Rhododendron 'Fragrantissimum Improved'
Similar to 'Fragrantissimum' but upright and much more compact, with deep green foliage and very fragrant flowers in larger trusses of up to 5.
Easy to grow.
Rhododendron 'Francesca'
Vigorous, rounded and open in habit, reaching up to 6 x 6 feet in 10 years, eventually up to 8 feet or more.
The ovate leaves, up to 7 x 2 inches, are deep green.
The intense deep red ( blackish-red in bud ) flowers, up to 3.5 inches across, are borne in large trusses of 19 to 25.
Hardy zones 6 to 8, tolerating as low as -15 F
* photos taken on May 14 2011 in Columbia, MD
Rhododendron 'Furnivall's Daughter'
The hybrid between Rhodo. caucasicum hybrid x griffithianum hybrid, forming vigorous, bushy, compact, large evergreen shrub. Some records include: 10 years - 5 feet; largest on record - 10 x 10 feet.
The large, wrinkled leaves, up to 6.5 x 3 inches, are glossy bright to mid-green.
The bright pink ( with deep red blotch ) funnel-shaped flowers, up to 3.5 inches across, are borne in pyramidal trusses of 15 during mid spring.
Hardy zones 4 to 8
Rhododendron 'Fusilier'
A vigorous, compact, medium-sized evergreen shrub, reaching a maximum size of 13 x 10 feet. Some records include: 10 years - 10 feet.
The large leaves, up to inches, are reddish at first, turning deep green above, hairy beneath. The leafstalks are also red.
The bright orange-red, funnel-shaped flowers are borne in mid-sized trusses during mid to late spring.
Hardy zones 5 to 9
Rhododendron 'Gill's Crimson'
A hybrid of unknown parentage, however certainly containing Rhodo. griffithianum. It forms a sturdy, upright, medium-sized evergreen shrub, reaching a maximum height of 13 feet. Some records include: 10 years - 6 feet.
The long oblong leaves are mid-green.
The intense red, funnel-shaped flowers are borne in dense, rounded trusses over a long season during early to mid spring.
Hardy zones 5 to 9
Rhododendron 'Ginny Gee'
The hybrid between R. keiskei & R. racemosum, forming a creeping to spreading, very dense, small evergreen shrub. Some records include: 10 years - 26 inches x 3 feet ( usually under a foot in height x 3 feet ); 20 years - 3 x 7 feet. Excellent for use in rock gardens, trailing over stone walls and on banks.
The stiff, small, elliptical leaves, up to 1.3 inches in length, are deep matte green turning burgundy-red in fall and winter. The leaves persist 2 to 3 years.
The very abundant, deep pink ( with white stripes ), funnel-shaped flowers, up to 1 inch across, are borne in trusses of 4 or 5 during early to mid-spring.
Hardy zones 4 to 8. Heat and cold tolerant, it is also more drought tolerant than most Rhododendrons.
Rhododendron 'Gladys'
An open medium-sized evergreen shrub, reaching a maximum size of 7 x 7 feet.
The leaves, up to 5 inches in length, are mid-green.
The bright yellow ( with deep red markings ), funnel-shaped flowers, up to 2 inches across, are borne in small, globular trusses of 10 during early to mid spring.
Hardy zones 5 to 9. Very heat, sun and wind tolerant.
Rhododendron 'Golden Star'
A compact, medium-size evergreen shrub that is the hybrid between Rhodo. fortunei & R. wardii. Some records include: 10 years - 5 feet; largest on record - 6 x 5 feet.
The elliptical leaves, up to 5 inches in length, are dull mid green and persisting up to 2 years.
The abundant, yellow, open funnel-shaped flowers, up to 3 inches across, are borne in full globular trusses of up to 13 during mid to late spring.
Hardy zones 5 to 9
Rhododendron 'Goldflimmer'
The hybrid between R. catawbiensis & R. ponticum, forming a strong growing, sturdy, dense, rounded to dome-shaped, medium-size evergreen shrub. Some records include: 10 years - 6.5 x 5 feet; largest on record - 10+ x 8 feet.
The very attractive leaves are glossy deep green and boldly variegated with a bright-yellow center blotch.
The purplish-pink, funnel-shaped flowers, up to 2 inches across, are borne in trusses of 9 to 14 during late spring.
Hardy zones 4 to 8
Rhododendron 'Goldsworth Orange'
The hybrid between R. dichroanthum & R. fortunei, forming a dense, upright to spreading, medium-size, evergreen large shrub. Some records include: 10 years - 5 feet.
The oblong leaves, up to 5 inches in length, are deep green. They are borne on red leafstalks.
The yellowish-orange ( orange throat and brown spotted ), funnel-shaped flowers are borne in lax trusses of 8 to 10, during late spring.
Hardy zones 6 to 8. Heat tolerant.
Rhododendron 'Gomer Waterer'
A very attractive, moderate growing, dense, upright to domed, large evergreen large shrub. Some records include: 10 years - 6 x 6 feet; largest on record - 15 x 15 feet.
The thick, leathery, oblong leaves, up to 5 inches in length, are glossy deep green.
The pure-white to bluish-white, funnel-shaped flowers, up to 3 inches across, are borne in trusses of up to 24, during mid to late spring. The flower buds are pink.
Hardy zones 4 to 8. Sun, heat and wind tolerant.
* photos taken on May 21 2018 in Columbia, MD
* photo taken on May 11 2021 in Columbia, MD
* photos taken by Milan Havlis, owner of central Europe's premier plant nursery
Rhododendron 'Haaga'
An upright, dense, medium-sized evergreen shrub, originating from the University of Helsinki, Finland. It is a hybrid partially originating from the extremely hardy Rhodo. brachycarpum ssp tigerstedtii. Some records include: 10 years - 5 x 5 feet; largest on record - 8 x 7 feet.
The coarse, narrow oblong leaves, up to 6 x 2 inches in size, are sulfur-yellow at first, turning to luxuriant glossy deep green.
The intense bright pink, funnel-shaped flowers, up to 2.7 inches across, are borne in 6 inch wide domed trusses of 15 to 20, during mid to late spring. The flowers are deep pink in bud.
Hardy zones 3 to 8, tolerating as low as -35 F. Among the hardiest of all Rhodos, it even grows in Winnipeg, Canada.
Rhododendron 'Hallelujah'
A very attractive, upright, medium-size, evergreen large shrub. Some records include: 10 years - 5 feet.
The very heavy textured, obovate leaves, up to 4.5 inches in length, are deep green. The foliage persists up to 3 years.
The intense purple-red, broad funnel-shaped flowers, up to 4 inches across, are borne in large, tight, rounded trusses of up to 10, during late spring.
Hardy zones 5 to 8 in partial shade
Rhododendron 'Harry Tag'
The hybrid between R. albescens & R. ciliicalyx, forming a compact, spreading, medium-size evergreen shrub. Some records include: 10 years - 4 feet.
The leathery, narrow, oblong leaves are deep green above, pale blue-green with golden-brown scales beneath.
The fragrant, white ( with light green-yellow stains ), frilly funnel-shaped flowers, up to 5 inches across, are borne in trusses of 3 or 4 over a long period during mid spring.
Hardy zones 8 to 9
Rhododendron 'Helene Schiffner'
A slow growing, compact, spreading, medium-size evergreen shrub, reaching a maximum height of 6 feet. Some records include: 10 years - 5 feet.
The attractive, narrow oblong leaves, up to 5 x 1.7 inches, are deep green above, gray-green beneath.
The pure white ( very faintly marked yellow to brown ), broad funnel-shaped flowers, up to 2 inches across, are borne in erect, domed trusses of 12 to 14 during mid spring.
The stems are red.
Hardy zones 4 to 8
Rhododendron 'Helliki'
A dense, small, evergreen shrub, reaching up to 6 x 6 feet, originating in Finland. It's parentage includes Rhodo. smirnowii. Some records include: 10 years - 5 x 5 feet.
The narrow, obovate leaves, up to 3.7 inches in length, are glossy deep green above, downy beneath.
The large, scarlet-red to deep violet-red, funnel-shaped flowers, up to 3 inches across, are borne in trusses of 8 to 12 during late spring.
Hardy zones 4 to 8, bud hardy to -30 F
Rhododendron 'Helsinki University'
The hybrid between R. brachycarpum tigerstedtii & R. smirnowii, forming a long-lived, compact, dense, upright, medium-sized, evergreen shrub that originated at the University of Helsinki, Finland. Some records include: 10 years - 7 x 6 feet; largest on record - 7 x 7 feet.
The large, narrow oblong leaves, up to 6 inches in length, are reddish at first, turning to glossy deep green.
The large, bright pink ( with orange flecks ), funnel-shaped flowers, up to 3 inches across, are borne in trusses of 12 to 18 during mid to late spring.
Hardy zones 3b to 7 tolerating as low as -40 F preferring light shade. It is among the hardiest of all Rhododendrons.
Rhododendron 'Holden'
The hybrid between R. catawbiense and R. 'Cunningham's White'. A compact shrub, reaching only 4 feet in 10 years, eventually up to 5 x 6 feet.
The foliage is luxuriant, glossy deep green.
The flowers are bright rosy-red.
Hardy zones 5b to 8 ( tolerating -15 F ).
* photos taken on May 4 2012 in Baltimore, MD
* photo taken on Apr 29 2022 in Elkridge, MD
* photo taken on Apr 24 2023 in Elkridge, MD
Rhododendron 'Honey Butter'
A new hybrid rhodo introduced by horticulturalist Jim Barlup. It is compact in habit, reaching up to 3 x 3 feet in 10 years, eventually to 4 x 5 feet.
The foliage is bronze-red at first, turning to glossy deep green.
The flowers are intense orange with a bright yellow center. The flower petals are edged in pink.
Hardy zones 7 to 9 in partial shade ( tolerates full sun in cool climates )
* photos taken on Apr 13 2022 in Ellicott City, MD
Rhododendron 'Hotei'
The hybrid of Rhodo. 'Goldworth Orange' x Rhodos (souliei x wardii ) forming an attractive, compact, bushy, medium-size evergreen shrub. Some records include: 10 years - 3 feet; largest on record - 8 x 8 feet.
The narrow-elliptic leaves, up to 5 inches in length, are deep green.
The deep yellow ( throated darker ), bell-shaped flowers, up to 2.5 inches across, are borne in loose rounded trusses of 10 to 12 during mid spring.
Hardy zones 6 to 9 requiring very well drained soil. Does not enjoy full sun.
Rhododendron 'Hummingbird'
The hybrid between R. haematodes & R. williamsonianum, forming a slow, growing, dense, compact, rounded, medium-size, evergreen shrub. Some records include: 10 years - 3.3 feet; largest on record - 6 x 6 feet.
The atractive, leathery, rounded leaves, up to 1.5 inches in length, are glossy deep green.
The intense deep red, bell-shaped flowers, up to 1.4 x 1 inch, are borne in loose trusses of 4 to 5 during early to mid spring.
Hardy zones 5 to 9, requires shade.
Rhododendron 'Janet Blair'
A handsome, very vigorous, dense, compact, rounded, medium-sized evergreen shrub. Some records include: 10 years - 6 x 7 feet; largest on record - 15 x 18 feet.
The elliptical leaves, up to 5 inches in length, are glossy deep green.
The large, fragrant, light pink ( with green flare on upper petal ), frilled, broad funnel-shaped flowers, up to 3.5 inches across, are borne in trusses of up to 13, during late spring. The flowers are deep pink in bud.
Hardy zones 5 to 8 tolerating as low as -20 F. Heat,cold and shade tolerant. It thrives especially well in coastal New England.
Rhododendron 'Jingle Bells'
A dense, compact, rounded, low evergreen shrub, reaching up to 3 feet in height. Some records include: 10 years - 3 feet.
The attractive elliptical leaves, up to 4 inches in length, are deep green.
The foliage persists for 2 years.
The orange ( with red throat ), funnel-shaped flowers, up to 3 inches across, are borne in lax trusses of 8 to 10 during mid spring. The flowers fade to yellow before falling.
Hardy zones 5 to 9
Rhododendron 'Lady Chamberlain'
The hybrid between Rhodo. cinnabarinum roylei x R. 'Royal Flush'. An upright to spreading, medium-size, evergreen shrub, reaching a maximum size of 10 x 5 feet. Some records include: 10 years - 5 feet.
The elliptical leaves are bluish-green at first, turning to deep blue-green.
The bright-orange to orange-pink, trumpet-shaped flowers are borne in hanging trusses of 3 to 6 during mid to late spring.
The branchlets are slender and long.
Hardy zones 7 to 9 requiring a site protected from excessive wind, such as a woodland understory.
Rhododendron 'Lady Clementine Milford'
A Rhodo. maximum hybrid, forming an attractive, vigorous, dense, upright, large evergreen large shrub. Some records include: 10 years - 5 x 6 feet; largest on record - 10 x 12 feet.
The leaves, up to 5.5 inches in length, are silvery-hairy at first, turning to glossy gray-green.
The abundant, peachy-pink ( edged darker ), funnel-shaped flowers are borne in domed trusses during mid to late spring.
Hardy zones 4 to 8. Sun, heat and cold tolerant.
Rhododendron 'Lady Rosebery'
The hybrid between Rhodo. cinnabarinum roylei x R. 'Royal Flush'. A medium-size, evergreen shrub. Some records include: 10 years - 5 feet; largest on record - 10 feet.
The leaves are blue-green, borne on red stalks.
The pink, funnel-shaped flowers are borne in trusses during mid spring.
Hardy zones 6 to 8, preferring a site protected from excessive wind.
Rhododendron 'Lavender Frost'
The hybrid between Rhodo. dauricum & R. 'Laurie'; forming an attractive, dense, upright, rounded, medium-sized evergreen shrub. Some records include: 10 years - 5 x 4 feet; largest on record - 5 x 6 feet.
The small, elliptical leaves, up to 1.7 inches, are bright green, turning to deep green. The foliage generally persists for 1 year.
The abundant, white to light-lavender, ruffled, double flowers are borne in domed trusses of 4, during mid spring.
Hardy zones 4 to 7 tolerating as low as -28 F, in sun to partial shade.
Rhododendron 'Lee's Dark Purple'
A Rhodo. catawbiense hybrid, forming a handsome, moderate growing, medium-sized evergreen shrub. Some records include: 10 years - 7 x 7 feet; largest on record - 22 x 15 feet.
The handsome large leaves are waxy glossy deep green. The foliage is similar to that of R. catawbiense.
The deep purple, funnel-shaped flowers, up to 2.7 inches across, are borne in trusses of up to 16 during late spring.
Hardy zones 5 to 8.
* photos taken on Sep 17 2012 in Columbia, MD
* photos taken on May 18 2013 in Columbia, MD
* photo taken on Apr 25 2014 in Columbia, MD
* photos taken on May 16 2014 in Columbia, MD
* photos taken on June 10 2014 in Columbia, MD
* photos taken on July 8 2014 in Columbia, MD
* photos taken on May 18 2015 in Columbia, MD
* photos taken on July 9 2015 in Columbia, MD
* photos taken on May 1 2017 in Columbia, MD
* photo taken on July 25 2017 in Columbia, MD
Rhododendron 'Lemon Mist'
The hybrid between Rhodo. xanthostephanum x R. leucaspis, forming a dense, spreading, small evergreen shrub. Some records include: 10 years - 3 x 6 feet; largest on record - 4 x 8 feet.
The elliptical leaves, up to 2.7 inches in length, are bright green.
The abundant, small, bright greenish-yellow, funnel-shaped flowers, up to 1.5 inches across, are borne in trusses of 2 or 3 during mid spring.
Hardy zones 7 to 9
Rhododendron 'Lem's Cameo'
A handsome, medium-sized evergreen shrub, reaching a maximum size of 7 x 7 feet. Some records include: 10 years - 6 x 4 feet.
The leaves, up to 4 inches in length, are bright bronze-red at first, turning to glossy deep-green.
The very abundant, pink and orangish-cream, broad bell-shaped flowers, up to 4 inches in length, are borne in large domed trusses of around 20 during mid to late spring.
Hardy zones 5 to 9. Difficult to propagate.
Rhododendron 'Lem's Monarch'
A vigorous, strong stemmed, dense, domed, large evergreen shrub. Some records include: 10 years - 6 x 7 feet.
The attractive rounded leaves, up to 8 inches in length, are bright-green turning to mid-green. The leafstalks are often reddish.
The pink, funnel-shaped flowers, up to 4 inches, are borne in huge heavy trusses ( up to 6 or more inches across ) during late spring.
Hardy zones 6 to 9 in sun to medium shade.
Rhododendron 'Letty Edwards'
The hybrid between Rhodo. campylocarpum elatum x R. fortunei. A compact, rounded, medium-size evergreen shrub, reaching a maximum height of 10 feet.
The leaves, up to 5 inches in length, are bright green, turning to mid-green. The leafstalks are red.
The very abundant, light yellow ( light pink in bud ), funnel-shaped flowers are borne in rounded trusses of 9 to 11 during mid spring.
Hardy zones 5 to 9
Rhododendron 'Loderi'
The hybrid between R. fortunei & R. griffithii, forming a evergreen massive shrub or small tree. Some records include: 10 years - 13 feet; largest on record - 33 feet with a trunk diameter of 1.5 feet.
The large, narrow, oblong leaves, up to 8 inches long, are mid-green.
The huge white flowers, up to 6 inches across, are borne in trusses of 9 to 12 during mid spring.
Hardy zones 6 to 9, preferring a woodland environment in partial shade with protection from excessive wind.
* historic archive photo
Rhododendron 'Loderi King George'
The hybrid between R. fortunei & R. griffithii, forming an evergreen small tree. Some records include: 10 years - 13 x 12 feet; largest on record - 33 feet with a trunk diameter of 1.5 feet.
The large, narrow oblong leaves, up to 10 inches in length, are luxuriant mid-green.
The very fragrant, very large, white, funnel-shaped flowers, up to 5 inches in length, are borne in loose trusses of 10 to 12 during mid spring.
The stems are deep red and the bark is smooth.
Hardy zones 6 to 9, preferring a woodland environment in partial shade with protection from excessive wind.
Rhododendron 'Loder's White'
The hybrid between Rhodo. arboreum ssp cinnamomeum var album x R. griffithianum, forming a dense, upright, evergreen, large shrub to small tree. Some records include: 10 years - 13 feet; largest on record - 20+ x 20 feet.
The large, narrow oblong leaves, up to 12 x 3 inches, are mid-green.
The abundant, lightly fragrant, white, broad funnel-shaped flowers, up to 5 inches in length, are borne in large, pyramidal trusses of up to 12, during mid spring.
Hardy zones 6 to 9, preferring a woodland environment in partial shade with protection from excessive wind.
Rhododendron 'Loderi Venus'
The hybrid between R. fortunei & R. griffithii, forming an evergreen small tree. Some records include: 10 years - 13 feet; largest on record - 33 feet with a trunk diameter of 1.5 feet.
The large leaves,up to 12 x 3 inches, are mid-green.
The very fragrant, very large, light pink, funnel-shaped flowers, up to 5.5 inches across, are borne in loose trusses of 9 to 12, during mid spring.
Hardy zones 6 to 8, preferring a woodland environment in partial shade with protection from excessive wind.
Rhododendron 'Markeeta's Prize'
The hybrid between Rhodo. 'Loderi Venus' & R. 'Anna'. A vigorous, very strong stemmed, stiff, upright, medium-size evergreen shrub. Some records include: 10 years - 5 feet; largest on record - 6 x 8 feet.
The thick, leathery leaves, up to 6 inches in length, are waxy deep green.
The huge, scarlet-red, funnel-shaped flowers, up to 5 inches across, are borne in giant trusses of 12 during mid spring.
Hardy zones 5 to 8
* photos taken by Milan Havlis, owner of central Europe's premier plant nursery
Rhododendron 'Matador'
The hybrid between Rhodo. griersonianum x R. strigillosum, forming an attractive, compact, medium-size evergreen shrub. Some records include: 10 years - 4 feet; largest on record - 6.5 feet.
The narrow elliptic leaves, up to 6 x 1.7 inches, are glossy deep green above, hairy beneath.
The deep orange-red, tubular flowers are borne in trusses of 8 during early to mid spring.
Hardy zones 5 to 9
Rhododendron 'May Day'
The hybrid between Rhodo. haematodes x R. griersonianum, forming a vigorous, fast growing, spreading medium-size, evergreen shrub. Some records include: 10 years - 3 x 4 feet; largest on record - 10 x 12 feet.
The elliptic leaves, up to 6 inches in length, are matt deep green above, white to tan woolly beneath.
The abundant, large, intense orange-red to scarlet-red, funnel-shaped flowers, up to 3 inches across, are borne in loose trusses of 8 during mid spring.
Hardy zones 5 to 9
Rhododendron 'Midnight'
A hybrid with Rhodo. 'Purple Splendour' as one of its parents, forming a vigorous, open, medium-size evergreen shrub. Some records include: 10 years - 5 x 5 feet; largest on record - 7 x 7 feet.
The lance-shaped leaves, up to 6 inches, are glossy deep green.
The intense red-purple ( spotted deep red and throated black ), broad funnel-shaped flowers are borne in rounded trusses of 16 during mid to late spring.
Hardy zones 4 to 8
Rhododendron 'Mikkeli'
The hybrid between brachycarpum ssp tigerstedti x R. smirnowii originating at the University of Helsinki, Finland. A vigorous, dense, compact, spreading, medium-sized evergreen shrub. Some records include: 10 years - 6 x 4 feet; largest on record - 6 x 6 feet.
The narrow oblong leaves, up to 7 inches in length, are whitish hairy at first, turning luxuriant glossy deep green.
The pure white ( with green spots and pink tints ), funnel-shaped flowers are borne in domed trusses of 10 to 18 during late spring.
Hardy zones 3 to 7 tolerating -40 F
Rhododendron 'Mindaura'
A medium-sized shrub, reaching up to 4 x 4 feet in 10 years, that is very similar to Rhodo. 'PJM' but is very compact and dense with intense lavender-pink flowers.
The deep matte green leaves turn bronze-purple during winter.
Hardy zones 4 to 8.
Rhododendron 'Minnetonka'
A Rhodo. ponticum hybrid, forming a dense, compact, medium-sized evergreen shrub. Some records include: 10 years - 4 x 5 feet; largest on record - 6 x 8 feet.
The elliptical leaves, up to 3.5 inches in length, are glossy deep green.
The light-purple ( with intense yellow-green spotting on the upper petal ), funnel-shaped flowers, up to 3 inches across, are borne in large, domed trusses of up to 15, during mid-spring. The flowers are deep purple in bud.
Hardy zones 4 to 8
* photos taken on May 1 2014 in Columbia, MD
* photos taken on Sep 26 2019 in Ellicott City, MD
Rhododendron 'Moonshine Crescent'
A upright, rounded, medium-sized evergreen shrub, reaching a maximum size of 8 x 8 feet.
The oval to oblong leaves are dull deep green.
The large, light yellow, bell-shaped flowers are borne in domed dense trusses during late spring.
Hardy zones 7 to 8
Rhododendron 'Moonstone'
The hybrid between Rhodo. campylocarpum ssp campylocarpum x R. williamsianum, forming a compact, dense, mounding, medium-size evergreen shrub. Some records include: 10 years - 3 x 4 feet; largest on record - 5 x 6 feet.
The oval, leaves are smooth deep green above, blue-green beneath.
The creamy-yellow, bell-shaped flowers are borne in loose trusses of 3 to 5 during early to mid spring.
Hardy zones 6b to 8 and sun tolerant. Prefers a cool climate however where late spring frosts are not a problem.
Rhododendron 'Mount Everest'
The hybrid between R. campanulatum & R. griffithianum, forming a vigorous, dense, evergreen small tree, reaching up to 12 x 12 feet. Some records include: 10 years - 7 x 7 feet.
The narrow elliptical leaves, up to 5.5 inches in length, are deep green.
The fragrant, large, pure white ( with maroon markings ) funnel-shaped flowers, up to 2.7 inches across, are borne in conical trusses of 10 to 12 during spring.
Hardy zones 6 to 8
Rhododendron 'Mrs. A.T. de la Mare'
A vigorous, dense, bushy, upright, rounded, medium-size evergreen shrub. Some records include: 10 years - 6.5 feet; largest on record - 10 x 10 feet.
The narrow elliptical leaves, up to 5.5 inches in length, are dull deep green.
The slightly fragrant, large, white ( faintly blotched green ), funnel-shaped flowers, up to 4 inches across, are borne in large, upright, domed trusses of 12 to 14 during mid to late spring. The flowers are pink in bud.
Hardy zones 4 to 8, prefers protection from excessive wind in cooler regions.
Rhododendron 'Mrs. Berry Robertson'
A compact, medium-size evergreen shrub, reaching a maximum size of 6 x 6 feet. Some records include: 10 years - 4 feet.
The thick, rough, pointed leaves, up to 4 inches in length, are green. The leaves are slightly pointed at the tip.
The soft yellow ( speckled red ) funnel-shaped flowers are borne in large, domed, upright trusses during mid spring.
Hardy zones 4 to 8
Rhododendron 'Mrs Charles E. Pearson'
The hybrid between Rhodo. 'Coombe Royal' & R. catawbiense 'Grandiflorum', forming a very vigorous, large evergreen shrub. Some records include: 10 years - 6 feet; largest on record - 15 x 12 feet.
The elliptical leaves, up to 8 inches in length, are luxuriant deep-green.
The light purplish-pink ( heavily spotted chestnut-brown ), funnel-shaped flowers, up to 2.7 inches across, are borne in huge, pyramidal trusses of up to 12 during mid to late spring.
Hardy zones 4 to 8. Tolerant of heat and sun.
Rhododendron 'Mrs' E.C. Stirling'
A hybrid of uncertain parentage other than that it includes Rhodo. griffithianum. It forms a moderate growing, strong, bushy, upright to spreading, medium-size evergreen shrub. Some records include: 10 years - 6 feet; largest on record - 10 x 10 feet.
The medium-sized, elliptical leaves that are luxuriant mid-green.
The abundant, pink, mid sized, slightly ruffled, broad funnel-shaped flowers, up to 3.5 inches across, are borne in trusses of up to 17, during mid to late spring.
Hardy zones 6 to 8. Sun tolerant.
Rhododendron 'Mrs. Furnivall'
A hybrid between Rhodo. griffithinum & R. caucasicum, forming an attractive, vigorous, compact, medium-size evergreen shrub, reaching a maximum size of 7 x 7 feet. Some records include: 10 years - 5 x 4 feet.
The attractive, elliptical leaves, up to 4 x 1.7 inches, are glossy deep green.
The rose-pink ( lighter in the center ), broad funnel-shaped flowers, up to 3.5 inches across, are borne in large domed trusses of 12 to 14, during mid to late spring.
Hardy zones 4 to 8, thrives in the Pacific Northwest as well as the eastern U.S. and Ontario, Canada. Heat tolerant.
Rhododendron 'Mrs G.W. Leak'
A vigorous, dense, upright, large evergreen shrub, reaching a maximum size of 16 x 16 feet. Some records include: 10 years - 13 feet.
The narrow, elliptical leaves, up to 8 x 2.7 inches, are smooth deep olive-green.
The pale pink ( with deep red markings and deep orange-red blotch )funnel-shaped flowers, up to 3.5 inches across, are borne in large, dense, pyramidal trusses of around 12, during mid-spring.
Hardy zones 7 to 8, easy to grow in sun or shade. Easy to grow from cuttings.
Rhododendron 'Naomi'
The hybrid between R. fortunei & R. 'Aurora' forming a dense, bushy evergreen small tree, reaching a maximum size of 20 x 15 feet. Some records include: 10 years - 10 feet.
The narrow oblong leaves, up to 8 inches in length, are rich deep green.
The fragrant, glowing mid-pink ( with yellow shading ) funnel-shaped flowers, up to 2 inches across, are borne in large, rounded trusses of 12 to 20, during late spring.
Hardy zones 6, tolerating -10 F
Rhododendron 'Nobleanum Venustum'
A hybrid between Rhodo. caucasicum x R. arboreum, forming a slow growing, dense, upright, medium-size, evergreen large shrub to small tree. Some records include: 10 years - 10 feet; largest on record - 17 x 17 feet.
The narrow oblong leaves, up to 7 inches in length, are deep green above, felted beneath.
The large, pink shading to white, broad funnel-shaped flowers, up to 2 inches across, are borne in compact trusses of 12 to 20, during very early spring.
Hardy zones 5 to 8, thrives in the dappeled shade and shelter of the woodland environment.
Rhododendron 'Northern Starburst'
A dense, sturdy, medium-sized evergreen shrub that looks similar to Rhodo 'PJM' but has stronger stems, much larger flowers and thick, larger, leathery leaves. In fact, it looks like a R. 'PJM' on steroids. Some records include: 10 years - 4 x 4 feet; largest on record - 5 x 5 feet.
The thick, oval leaves, up to 2.5 inches in length, are bright green, turning to deep green in summer, then to blackish-purple during autumn and winter.
The bright pink, funnel-shaped flowers, up to 2.5 inches across, are borne in trusses of 4 to 5, during early spring. The flowers are red in bud.
Hardy zones 4 to 8 tolerating as low as -25 F
* photos taken on Apr 10 2018 in Columbia, MD
Rhododendron 'Olga Mezzitt'
The hybrid between R. minus & R. carolinianum, forming an attractive, fast growing, broad, upright, medium-sized evergreen shrub that is similar to Rhodo 'PJM'. It tolerates shearing well as long as it is done immediately after blooming, resulting in a denser shrub. Some records include: fastest recorded growth rate - 15 inches; 10 years - 5 x 4 feet; largest on record - 8 x 8 feet.
The aromatic, oval leaves, up to 2 inches in length, are bright green, turning to glossy deep green in summer, then to deep red-bronze during fall and winter.
The very abundant, clear mid-pink, funnel-shaped flowers, up to 1.5 inches across, are borne in domed trusses of up to 12 over a 2 week period during during mid-spring. The flowers appear 2 weeks after Rhodo 'PJM'.
Hardy zones 4 to 8 tolerating as low as -25 F. Sun tolerant.
* photo taken on Apr 6 2013 in Howard Co., MD
* photos taken on Aug 9 2018 in Ellicott City, MD
* photo taken on Oct 18 2019 in Ellicott City, MD
* photos taken on July 10 2023 @ Collingwood Arboretum, Collingwood, ON
Rhododendron 'Pekka'
Reaches up to 9 x 8 feet, bearing light pink flowers in profuse, domed trusses.
Hardy zones 4a to 8 ( tolerating -30 F ). Known to thrive in Finland.
Rhododendron 'Pink Pearl'
A vigorous, open, upright, spreading evergreen small tree. Some records include: 10 years - 8 x 6 feet; largest on record - 20 x 18 feet.
The thick, elliptical leaves, up to 6 x 2 inches in length, are glossy deep green.
The rose-pink, funnel-shaped flowers, up to 4.5 inches across, are borne in large, dense, pyramidal trusses of up to 18, during mid to late spring. The flowers are deep pink in bud.
Hardy zones 6 to 8
Rhododendron 'PJM'
The hybrid between R. carolinianum & R. dauricum forming a moderate growing, upright, dense, medium-size, evergreen shrub. Some records include: fastest recorded growth rate - 2 feet; 10 years - 8 x 5 feet; largest on record - 15 x 7 feet ( rarely over 9 x 6 feet - can be kept pruned lower ).
The aromatic, elliptical to rounded leaves are up to 3.5 inches in length. The leathery foliage is glossy deep green turning to bronze-purple during winter.
The bright lavender-pink, funnel-shaped flowers, up to 1.5 inches across, are borne in rounded trusses of 10 to 15, during early spring. Rarely sets seed thus not needing to be deadheaded.
Hardy zones 4 to 8 tolerating as low as -35 F, surviving even in south-central & southeastern Alaska. May be vegatatively hardy north to zone 3a. The flower buds are killed at -30 F. It is important to mulch during the winter because the roots are less hardy and can be killed at 0 F if exposed. Sun and heat tolerant.
* photo taken on Sep 17 2012 in Ellicott City, MD
* photo taken on Nov 30 2013 in Luzerne Co., MD
* photo taken on Apr 22 2015 in Columbia, MD
* photos taken on June 20 2015 in Columbia, MD
* photos taken on Mar 31 in Columbia, MD
* photo taken on Dec 23 2015 in Columbia, MD
* photo taken on Jan 29 2016 in Columbia, MD
* photo taken on May 22 2019 in Columbia, MD
* photos taken on Mar 20 2020 in Columbia, MD
* photos taken on Apr 22 2022 in Kingston, PA
* photos taken on Mar 29 2023 in Columbia, MD
* photos taken on Mar 24 2024 in Columbia, MD
Rhododendron 'PJM Elite'
Very heat tolerant with very abundant, lavender-pink flowers that emerge mid-spring rather than early spring. Otherwise very similar to Rhodo. 'PJM'.
* photo taken on Apr 18 2017 in Columbia, MD
* photos taken on May 22 2019 in Columbia, MD
* photo taken on Sep 22 2020 in Columbia, MD
* photos taken on Apr 14 2021 in Columbia, MD
* photos taken on July 10 2023 @ Collingwood Arboretum, Collingwood, ON
* photos taken on Apr 15 2024 in Columbia, MD
Rhododendron 'Polar Bear'
The hybrid between Rhodo. auriculatum & R. diaprepes, forming a very vigorous, rapid growing, small evergreen tree. Some records include: 10 years - 20 x 13 feet; largest on record - 37 x 40 feet with a trunk diameter of 21 inches.
The heavily-veined, long, oblong to elliptic leaves, up to 12 inches, are deep green.
The very fragrant, large, pure white ( speckled green ), funnel-shaped flowers, up to 4 inches across, are borne in trusses of 8 to 10 during early summer.
The attractive bark is brown and flaking.
Hardy zones 6 to 9 preferring a shaded woodland environment..
Rhododendron 'Praecox'
The hybrid between R. ciliatum & R. dauricum forming an attractive, dense, rounded, small, evergreen shrub. Some records include: 10 years - 6.6 x 8 feet; largest on record - 10 x 10 feet. Looks great planted with yellow crocuses and snowdrops.
The ovate to oblong leaves, up to 2.7 inches in length, are glossy deep green above,paler beneath. May be semi-evergreen in cold climates.
The abundant, violet-purple, broad funnel-shaped flowers, up to 1.7 inches across, are borne in trusses of 2 or 3, during early spring.
Hardy zones 6 to 8 preferring a sheltered site.
* historic archive photos
Rhododendron 'Princess Alice'
The hybrid between Rhodo. edgeworthii x R. ciliatum, forming a compact, small evergreen shrub, reaching a maximum height of 6 feet. Some records include: 10 years - 5 feet.
The heavily-textured, oval leaves, up to 4 inches, are deep green.
The fragrant, white ( with small yellow eye ), funnel-shaped flowers are borne in loose trusses during early to mid spring. The flowers are often flushed pink.
Hardy zones 7 to 9. Sun tolerant and easy to grow.
Rhododendron 'Prostigiatum'
The hybrid between Rhodo. saluenense ssp chameunum 'Prostratum' & R. fastigiatum. A very slow growing, small evergreen shrub.
The tiny leaves are gray-green.
The rich, deep-purple, funnel-shaped flowers, up to 2 inches across, are borne in trusses of 2 or 3 during mid to late spring.
Hardy zones 6b to 9
Rhododendron 'Ptarmigan'
A compact, twiggy, spreading, low prostrate to mounding, evergreen shrub. Some records include: 10 years - 1 feet; largest on record - 3 x 3 feet. It is an excellent plant for use in rock gardens.
The small oblong leaves, up to 1.3 inches, are deep green above, densely scaly beneath.
The pure white, broad funnel-shaped flowers, up to 1 inch across, are borne in terminal trusses of 2 or 3 during early to mid spring.
Hardy zones 4 to 8
Rhododendron 'Purple Gem'
The hybrid between R. fastigiatum & R. carolinianum forming a slow growing, medium-sized evergreen shrub, reaching a maximum size of 3 x 5 feet. Some records include: 10 years - 2 x 4 feet.
The aromatic leaves are gray-blue at first, turning blue-green above, rusty-orange felted beneath. The foliage turns to purplish-bronze during winter.
The purple-violet, funnel-shaped flowers are borne in rounded trusses during mid-spring. It sometimes reblooms during mid autumn.
Hardy zones 5 to 8 ( zone 4 with snow cover or extra winter protection ), tolerating as low as -25 F
* photo taken on Apr 11 2015 in Elkridge, MD
* photos taken on July 9 2015 in Columbia, MD
* photos taken on Oct 1 2016 in Annapolis, MD
* photo taken on Apr 5 2021 in Elkridge, MD
* photo taken on Mar 25 2023 in Elkridge, MD
Rhododendron 'Purple Passion'
A fast growing, sturdy, compact, upright, medium-size, evergreen shrub that is a hybrid of Rhodo. ponticum. Some records include: 10 years - 5 feet; largest on record - 10 x 10 feet. Looks amazing planted with white or yellow flowers.
The elliptical leaves, up to 6 x 2.5 inches, are glossy deep green.
The large, deep violet-purple ( blotched black ), ruffled, broad funnel-shaped flowers, up to 3.3 inches across, are borne in domed trusses of up to 15, during mid to late spring.
Hardy zones 4 to 8 in sun or shade. Easy to propagate.
* photos taken on May 5 2010 in Columbia, MD
'Ramapo'
The hybrid between R. fastigiatum & R. carolinianum forming a bushy, dense, compact, low growing, evergreen shrub. Some records include: 5 years - 2 x 2 feet; largest on record - 4 x 5.5 feet. It is excellent for a rock garden or low border.
The very aromatic, small, rounded leaves, up to 1 inch in length, are gray-blue at first, turning to blue-green.
The abundant, light violet-blue, funnel-shaped flowers, up to 1 x 1 inch, are borne in small trusses during early to mid spring.
Hardy zones 5 to 8, tolerating as low as -25 F or even colder ( reported as far north as zone 3 where snowfall is reliable ). Sun tolerant.
* photo taken on Mar 14 2010 in Columbia, MD
* photo taken on April 10 2010 in Howard County, MD
Rhododendron 'Rangoon'
A spreading, medium-sized evergreen shrub. Some records include: 10 years - 4 x 6 feet; largest on record - 4 x 8 feet.
The long, elliptical leaves, up to 3.5 inches in length, are glossy deep green. The foliage persists up to 2 years and the leaf stalks are deep red.
The deep red ( with no markings ), funnel-shaped flowers, up to 2 inches across, are borne in domed trusses of 7 or 8 during early summer. The flowers are also deep red in bud.
Hardy zones 5 to 8 ( tolerating -20 F ).
Rhododendron 'Red Armiral'
The hybrid between R. arboreum & R. thompsonii forming a large evergreen shrub that may be almost tree-like in habit. Some records include: 10 years - 7 feet; largest on record - 20 feet.
The large, oblong leaves are deep green. The foliage is typically held just over a year.
The glowing, rich scarlet-red, bell-shaped flowers are borne in trusses during early spring.
Hardy zones 6 to 8
Rhododendron 'Roman Pottery'
A compact, rounded, small evergreen shrub, reaching a maximum height of 3 feet.
The leaves are green.
The light orange, funnel-shaped flowers are borne in loose pendulous trusses during mid spring.
Hardy zones 5 to 9
Rhododendron 'Romany Chal'
The hybrid between Rhodo. Moser's Maroon & R. eriogynum, forming a vigorous, upright, large evergreen shrub. Some records include: 10 years - 6.5 feet.
The leaves are green.
The glowing deep red, funnel-shaped flowers are borne in trusses during early summer.
Hardy zones 6, preferring the dappled shade and protection from wind that is found in the woodland environment.
Rhododendron 'Russautinii'
A fast growing, medium-sized evergreen shrub, reaching a maximum height of 5 feet.
The small leaves are green.
The abundant, lavender-blue ( with darker eye ), funnel-shaped flowers are borne in trusses of 2 to 5 during early to mid spring.
Hardy zones 4 to 8
Rhododendron 'Ruby Hart'
The hybrid between Rhodo. elliottii & R.( Carmen x Elizabeth ), forming a compact, dense, mounding, small evergreen shrub. Some records include: 10 years - 3 x 3 feet.
The elliptical leaves, up to 2.5 inches in length, are very glossy, blackish-green above, gray-brown hairy beneath.
The waxy deep-red, broad funnel-shaped flowers, up to 1.5 inches across, are borne in loose trusses of 7 during early to mid spring.
Hardy zones 6 to 9
Rhododendron 'Russautinii'
The hybrid between Rhodo. russatum x R. augustinii forming an upright, medium-sized evergreen shrub. Some records include: 10 years - 6.5 feet; largest on record - feet.
The narrow-elliptical leaves, up to 4 inches, are deep green. The foliage is unfortunately prone to leaf spot in some regions.
The deep lavender-blue funnel-shaped flowers are borne in trusses during mid-spring.
Hardy zones 6 to 8
Rhododendron 'Russellianum'
The hybrid between R. arboreum & R. catawbiense forming a very vigorous, evergreen small to medium size tree. Some records include: 10 years - 10+ feet; largest on record - 50+ feet with a trunk diameter of 22 inches. It is among the most spectacular of all hybrid Rhododendrons and should be planted far more often.
The large, oblong leaves are deep green.
The rosey-red funnel-shaped flowers are borne in trusses during spring.
Hardy zones 6 to 8
Rhododendron 'Saffron Queen'
The hybrid between Rhodo. xanthostephanum x R. burmanicum, forming a compact, spreading, small evergreen shrub. Some records include: 10 years - 6 x 8 feet; largest on record - 7 x 9 feet.
The narrow-elliptical leaves, up to 3.5 inches in length, are glossy deep green.
The abundant, mid-yellow ( dark spotted ), funnel-shaped flowers are borne in small trusses of 8 to 9 during early to mid spring.
The attractive bark is cinnamon-brown and peeling.
Hardy zones 7 to 9
Rhododendron 'Saint Tudy'
A vigorous, small evergreen shrub. Some records include: 10 years - feet; largest on record - 6.5 feet.
The leaves are green.
The violet-blue, funnel-shaped flowers, up to 2 inches in length, are borne in trusses of 14 during early to mid spring.
Hardy zones 4 to 8
Rhododendron 'Sapphire'
The hybrid between Rhodo. 'Blue Tit' & R. impeditum, forming a bushy spreading, dwarf small evergreen shrub. Some records include: 10 years - 2.5 feet; largest on record - 3.3 feet.
The small leaves, up to 0.7 inches in length, are glossy blue-green.
The light blue, funnel-shaped flowers, up to 1.3 inches across, are borne in rounded trusses of 4 to 5 during mid spring.
Hardy zones 6b to 9, tolerating as low as -5 F
Rhododendron 'Sappho'
A fast growing, evergreen small tree of unknown parenteage. Some records include: 10 years - 10 feet; largest on record - 20 x 20 feet ( typically 12 x 10 feet ).
The narrow-elliptical leaves, up to 7 x 2.5 inches, are glossy olive deep green.
The mid-sized, white ( blotched deep red-purple ), broad funnel-shaped flowers, up to 3.5 inches across, are borne in large pyramidal trusses of up to 15, during mid to late spring.
Hardy zones 4 to 8. Regular pruning helps keep it compact.
* historic archive photo
Rhododendron 'Scarlet Romance'
An extremely attractive, dense, upright, medium-sized evergreen shrub. Some records include: 10 years - 6 x 6 feet; largest on record - 6 x 10 feet.
The elliptical leaves, up to 6 inches in length, are glossy deep green.
The abundant, purplish-red, funnel-shaped flowers, up to 3.5 inches across, are borne in conical trusses of 15 to 20 during late spring.
Hardy zones 5 to 8 ( bud hardy to as low as -25 F or even colder ).
Rhododendron 'Scarlet Wonder'
The hybrid between Rhodo. 'Essex Scarlet' x R. forrestii ssp forrestii, forming a vigorous, dense, compact, small evergreen shrub. Some records include: 10 years - 2 x 4.5 feet; largest on record - 3 x 7 feet.
The deeply-veined, broad-oblong to elliptical leaves, up to 2 inches in length, are glossy deep green.
The intense scarlet-red, bell-shaped flowers, up to 2.3 inches across, are borne in loose trusses of 5 to 7 during mid spring.
Hardy zones 5 to 8. Prefers sun. It does not enjoy hot humid summers but does well in the Pacific Northwest and some of the more maritime parts of the northeast.
Rhododendron 'Scintillation'
A vigorous, sturdy, broad, dense, medium-sized, evergreen shrub that is a hybrid of Rhodo. fortunei. Some records include: 10 years - 5 x 6 feet; largest on record - 10 x 14.5 feet.
The attractive, heavy-textured, wavy-edged, oblong leaves, up to 6 inches in length, are waxy, very glossy deep olive-green.
The abundant, pink, funnel-shaped flowers, up to 2.5 x 2.5 inches, are borne in large trusses of 11 to 15 during mid spring.
Hardy zones 4 to 8 ( flower bud hardy to as low as -24 F ). Heat tolerant.
* photos taken on July 9 2015 in Columbia, MD
* photos taken on Oct 13 2015 in Howard Co., MD
* photos taken on May 9 2016 in Columbia, MD
* photos taken on June 29 2016 in Columbia, MD
* photo taken on May 2 2017 in Columbia, MD
* photos taken on July 25 2017 in Columbia, MD
* photos taken on July 13 2021 @ Hershey Gardens, Hershey PA
Rhododendron 'Seta'
The hybrid between R. spinuliferum & R. moupinense, forming a compact, upright, medium-sized evergreen shrub. Some records include: 10 years - 5 x 5 feet; largest on record - 7 x 7 feet.
The narrowly oval leaves, up to 2 inches in length, are glossy, very deep green. The foliage persist up to 3 years.
The very abundant, very slender, white ( boldly longitudinally striped rosey-pink ) bell-shaped flowers are borne in loose trusses over a long season during early spring.
Hardy zones 5 to 8, prefers partial shade and a woodland understory position protected from excessive wind and late spring frost.
Rhododendron 'Seven Stars'
The hybrid between Rhodo. 'Loderi Sir Joseph Hooker' & Rhodo. degronianum ssp yakushimanum, forming a vigorous, dense, compact, upright medium-sized evergreen shrub. Some records include: 10 years - 5 feet; largest on record - 10 x 10 feet.
The narrow oblong leaves, up to 5.7 inches, are glossy deep green.
The abundant, white with pink flushing, bell-shaped flowers, up to 2 inches across, are borne in small dense, domed trusses of 12 to 15, during late spring. The flowers are pink in bud.
Hardy zones 7 to 8
Rhododendron 'Shammarello'
A moderate growing, upright, rounded, dense, medium-sized evergreen shrub. Some records include: 10 years - 4 x 4 feet; largest on record - 5 x 5 feet.
The thick, large, leaves are bronze at first, turning to glossy deep green.
The intense, pinkish-purple ( with a deep red blotch ), funnel-shaped flowers are borne in large trusses during spring.
Hardy zones 5 to 8
Rhododendron 'Sir Charles Lemon'
Though parentage isn't certain, it is likely a form of Rhodo. arboreum ssp cinnamomeum var. album. A very vigorous, stunning, bushy, small evergreen tree. Some records include: 10 years - 10 feet; largest on record - 30 x 30 feet.
The long narrow leaves are whitish downy at first, turning to very deep green above, intense rust-orange hairy beneath.
The pure white ( with some purple spotting ), funnel-shaped flowers are borne in large, globular trusses of about 10 during early to mid summer.
Hardy zones 6 to 9
Rhododendron 'Smithii'
A evergreen small tree, reaching a maximum size of 57 feet with a trunk diameter of 26 inches.
The leaves are green.
The funnel-shaped flowers are borne in trusses during spring.
Hardy zones
Rhododendron 'Snow Lady'
The hybrid between R. leucapis & R. ciliatum forming a spreading, compact, small evergreen shrub. Some records include: 10 years - 3 feet; largest on record - 5 feet.
The elliptic, leaves, up to 3 inches in length, are hairy glossy deep green.
The pure white, funnel-shaped flowers, up to 2.5 inches across, are borne in loose trusses of up to 8, during early spring, often at the same time as the Crocus's.
Hardy zones 5 to 9, sun and deep shade tolerant. Easily grown from cuttings.
Rhododendron 'Snow Queen'
The hybrid between Rhodo. 'Halopeanum' & Rhodo 'Loderi', forming a vigorous, evergreen large shrub to small tree. Some records include: 10 years - 5 feet; largest on record - feet.
The leaves are green.
The fragrant, pure white ( with very small red blotch ), funnel-shaped flowers are borne in trusses during late spring. The flowers are deep pink in bud.
Hardy zones 6 to 8 preferring a shaded woodland environment.
Rhododendron 'Songbird'
The hybrid between Rhodo. russatum x R. 'Blue Tit', forming a dense, compact, medium-sized evergreen shrub. Some records include: 10 years - 3 feet; largest on record - 5 feet.
The small, oval leaves are glossy deep green.
The glowing, bright intense purple-blue, bell-shaped flowers, up to 1 inches across, are borne in trusses of up to 20, during mid spring.
Hardy zones 6 to 8, tolerating as low as -10 F.
Rhododendron 'Souvenir de Dr. S. Endtz'
The hybrid between Rhodo. 'Pink Pearl' & Rhodo. 'John Walter', forming a vigorous, medium-sized evergreen shrub. Some records include: 10 years - 7 x 10 feet; largest on record - 10 x 13 feet.
The leaves, up to 8 inches in length, are deep green.
The rich pink ( with deep red ray marking ), broad funnel-shaped flowers, up to 3 inches across, are borne in domed trusses of 15 to 17 during mid spring.
The flowers are rosey-pink in bud.
Hardy zones 4 to 8. Tolerant of sun and rarely bothered by insect pests.
Rhododendron 'Staccato'
An attractive, upright, medium-sized evergreen shrub that originated from the popular Rhodo 'PJM'. Some records include: 10 years - 5 x 4 feet; largest on record - feet.
The leaves are luxuriant green, turning a very beautiful warm bronzy-red in fall.
The profuse, deep pink, double flowers are borne in trusses during
Hardy zones 4 to 8
Rhododendron 'Suaive'
A compact, small evergreen shrub. Some records include: 10 years - feet; largest on record - 3 feet.
The leaves are green.
The fragrant, white to blush-pink ( fading to white ), bell-shaped flowers are borne in trusses during early to mid-spring.
Hardy zones 5 to 9
Rhododendron 'Susan'
The hybrid between R. campanulatum & R. fortunei, forming a fast growing, dense, bushy, upright to spreading, large evergreen large shrub. Some records include: 10 years - 10 x 10 feet; largest on record - 13 x 13 feet.
The broadly elliptic leaves, up to 6 inches in length, are glossy deep green. The leafstalks are purple.
The light blue-pink to violet-blue ( margined and spotted darker ), funnel-shaped flowers, up to 3.5 inches across, are borne in dense, large, rounded trusses of 12 to 16 during mid to late spring.
Hardy zones 4 to 8 in sun or partial shade. Disease resistant.
Rhododendron 'Tally Ho'
The hybrid between Rhodo. griersonianum & R. eriogynum, forming a very attractive, dense, upright, medium-sized evergreen shrub. Some records include: 10 years - 6 feet; largest on record - 8 x 9 feet.
The twisted, narrow-elliptical leaves, up to 5 inches in length, are brown felted at first, turning to deep green above, light-brown felted beneath.
The intense orange-red, broad funnel-shaped flowers, up to 2 inches across, are borne in dense trusses of up to 14, during early summer.
Hardy zones 7 to 9 preferring a woodland environment protected from hot sun and wind.
Rhododendron 'Tapestry'
The hybrid between R. catawbiensis & R. 'Purple Splendour' forming a dense,
compact, sturdy medium-sized evergreen shrub. Some records include: 10 years - 6 x 6 feet; largest on record - 18 feet.
The long, elliptical leaves are luxuriant bright green, later turning to glossy deep green. The foliage persists for 2 years.
The vivid purple ( with darker purple eye ), broad funnel-shaped flowers, up to 2 inches across, are borne in domed trusses of 18, during late spring.
Hardy zones 5a to 8, tolerating as low as -25 F
Rhododendron 'Taurus'
The hybrid between Rhodo 'Jean Marie de Montague' x R. strigillosum, forming a spectacular, vigorous, upright, large evergreen shrub. Some records include: 10 years - 6 x 6 feet; largest on record - 10 x 10 feet.
The attractive, long narrow elliptic leaves, up to 7 inches in length, are deep green above, white felted beneath. The foliage persists up to 3 years.
The intense deep red ( with black spotting ) funnel-shaped flowers, up to 3.5 inches in length, are borne in rounded trusses of 16 during mid-spring.
Hardy zones 6b to 9, tolerating as low as -5 F. Prefers a shaded woodland environment.
* photo taken on Apr 25 2020 in Howard Co., MD
* photo taken on Sep 10 2022 in Elkridge, MD
* photo taken on July 16 2023 in Elkridge, MD
Rhododendron 'Temple Bell'
The hybrid between R. obiculare × R. williamsianum forming an attractive compact, low, mounded evergreen shrub. Some records include: 10 years - 5 feet; largest on record - feet.
The thick, rounded leaves, up to 3 x 1 inches, are bronze at first, turning to deep green above, white beneath. The edges of the leaves roll downward.
The soft-pink, funnel-shaped flowers are borne in trusses during early spring.
The flowers, up to 2 inches across, are borne in loose trusses of 5 to 6 during mid spring. They are deep pink in bud.
Hardy zones 6 to 8
Rhododendron 'Tessa'
The hybrid between R. moupinense & R. praecox forming a vigorous, upright, small, evergreen shrub. Some records include: 10 years - 4 feet; largest on record - feet.
The small, oval leaves are glossy deep green.
The purple-pink ( spotted deep-red ), funnel-shaped flowers, up to 2.5 inches across, are borne in loose trusses of 3 or 4 during very early spring.
The attractive, peeling bark is red-bronze.
Hardy zones 7 to 9, tolerating as low as -5 F
Rhododendron 'The Honorable Marie de Montague'
A hybrid of unknown parentage but certainly containing Rhodo. griffithianum; it forms a compact, densespreading, medium-sized evergreen shrub. Some records include: 10 years - 6 x 6 feet; largest on record - 8 x 8 feet.
The heavily-textured, thick, leathery, curved, narrow elliptical leaves, up to 9 x 2.5 inches, are verdant deep-green.
The large, scarlet-red, broad funnel-shaped flowers, up to 3.3 inches across, are borne in domed trusses of 10 to 14 during mid spring.
Hardy zones 6 to 8, tolerating as low as -10 F. Heat and sun tolerant.
Rhododendron 'Trewithen Orange'
The hybrid of Rhodo. 'Full House' & Rhodo. cinnabarinum ssp xanthocodon, forming an erect medium-size evergreen shrub. Some records include: 10 years - 5 feet; largest on record - 6 feet.
The elliptical leaves are very glossy blue-green.
The orange-brown, tubular flowers are borne in loose, hanging trusses of 5, during mid spring.
Hardy zones 6b to 9
Rhododendron 'Trude Webster'
An attractive, moderate growing, compact, upright, medium-size evergreen shrub. Some records include: 10 years - 5 x 5 feet; largest on record - 7 x 7 feet.
The large, broad, elliptic, slightly twisted leaves, up to 8 inches in length, are glossy mid-green.
The clear mid-pink, funnel-shaped flowers, up to 5 inches across, are borne in huge, dense, upright trusses, up to 14 inches across, during mid spring.
Hardy zones 6 to 8 ( tolerating -10 F ).
Rhododendron 'Tyermanii'
The hybrid between R.formosum & R. nuttallii forming a compact, small evergreen shrub. Some records include: 10 years - 5 feet; largest on record - 5 feet.
The, deeply veined, large leaves are glossy deep green.
The very large, very fragrant, pure white ( with yellow stain in throat ), funnel-shaped flowers are borne in lax trusses of 3 or 4during mid to late spring.
The attractive bark is rich-brown.
Hardy zones 7 to 9
Rhododendron 'Unique'
A hybrid of Rhodo. campylocarpum, it forms a very attractive, moderate growing, handsome, compact, very dense, medium-sized evergreen shrub. Some records include: 10 years - 4 x 4 feet; largest on record - 6 x 6 feet.
The thick, oblong leaves, up to 4 x 2 inches, are glossy deep green.
The very abundant, orangish-pink ( fading to cream ), funnel-shaped flowers, up to 2.7 inches across, are borne in mid-sized, domed trusses of up to 14, during early to mid spring. The flowers are bright pink in bud.
Hardy zones 6 to 8 though preferring shade in warmer climates. Thrives in neutral or acidic soil.
'Unique Variegated'
Very similar to 'Unique' except for the variegated foliage which is margined in creamy-green turning to golden-green.
Rhododendron 'Vanessa Pastel'
A moderate growing, compact, upright to spreading, medium-sized evergreen shrub. Some records include: 10 years - 5 feet; largest on record - 6.5 feet.
The pointed, narrow ovate leaves, up to 7 inches, are slightly hairy, deep-green above.
The funnel-shaped flowers, up to 5 inches across, are borne in trusses of 8 during mid to late spring. The flowers are orange-red at first, turning to apricot-orange then finally fading to creamy-yellow with the throat being deeper bronzy-yellow.
Hardy zones 7 to 9
Rhododendron 'Vulcan's Flame'
The hybrid between R. griersonianum & R. 'Mars' forming a compact, medium-sized evergreen shrub. It is a more vigorous, larger leafed superior form of Rhodo. 'Vulcan'. Some records include: 10 years - 5 x 6 feet; largest on record - 10 x 8 feet ( typically matures around 6 x 6 feet ).
The pointed, elliptical leaves, up to 8 inches in length, are glossy deep green. The leafstalks are red.
The intense fiery-red, funnel-shaped flowers, up to 2.5 x 3 inches, are borne on heavy trusses during late spring.
The stems are reddish.
Hardy zones 5 to 8. It is much easier to grow and is both more heat and cold tolerant than Rhodo. 'Vulcan' which is only hardy to zone 6 ( -15 F ). Sun and moderately drought tolerant.
* photos taken on May 14 2012 in Howard Co., MD
* photos taken on July 20 2014 in Columbia, MD
* photo taken on June 9 2016 in Columbia, MD
* photo taken on June 29 2016 in Columbia, MD
* photos taken on May 8 2017 in Columbia, MD
* photo taken on Apr 10 2021 in Columbia, MD
Rhododendron 'Waltham'
A compact, low evergreen shrub, reaching a maximum size of 2 x 5 feet.
The beautiful, thick, oval leaves, up to inches, are very glossy deep green.
The clear pink, tubular flowers, up to inches in length, are borne in trusses during
Hardy zones 5 to 8
Rhododendron 'War Dance'
A broad, medium-sized evergreen shrub. Some records include: 10 years - 4 x 5 feet.
The elliptical leaves, up to 5.3 inches in length, are deep green. The foliage persists for 2 years.
The funnel-shaped flowers, up to 2.7 inches across, are borne in rounded trusses of 17 to 21 during mid to late spring.
Hardy zones 6 to 8, tolerating as low as -10 F
Rhododendron 'Wedding Gown'
An open, broad, medium-size evergreen shrub, reaching a maximum height of 5 feet.
The leaves, up to inches, are mid-green.
The yellowish-white, funnel-shaped flowers are borne in trusses of 5 to 7 during spring.
Hardy zones 5 to 9
Rhododendron 'Weston's Pink Diamond'
The hybrid between Rhodo. 'PJM' x Rhodo. mucronulatum 'Cornell Pink'. A vigorous, dense upright to eventually spreading, medium-sized evergreen shrub. Some records include: 10 years - 8 x 8 feet; largest on record - 12 x 12 feet.
The aromatic leaves, up to 1.5 inches, are glossy mid-green, turning very attractive orange, red and yellow during autumn, often with all colors on the same plant.
The double, sparkling rosey-pink, frilled flowers, up to 1.3 inches across, are borne in trusses of 8 to 12 during early spring ( 2 weeks before Rhodo 'PJM' ).
Hardy zones 4 to 8
Rhododendron 'White Peter'
A Rhodo. ponticum hybrid, forming a vigorous, compact, bushy, medium-size, evergreen shrub. Some records include: fastest recorded growth rate - 1.5 feet; 10 years - 10 x 6 feet; largest on record - 10 x 17.5 feet.
The long, elliptical leaves, up to 7 inches in length, are glossy deep green.
The abundant, white ( with deep red flare ), frilled, funnel-shaped flowers, up to 2.8 inches across, are borne in tight, pyramidal trusses of up to 15, during late spring.
Hardy zones 3b to 8 ( tolerating -40 F ) in sun or shade. Tolerant of heat and sun. Easy to grow from cuttings.
Rhododendron 'Windbeam'
A rounded, medium-sized evergreen shrub. Some records include: 10 years - 3 feet; largest on record - 5 x 6 ( rarely over 4 x 4 ) feet.
The elliptical leaves, up to 2.7 inches, are olive-green, turning to bronze in winter. The foliage is aromatic.
The translucent pink, funnel-shaped flowers, up to 0.7 inches across, are borne in rounded trusses of 8 during
Hardy zones 4 to 8, it thrives especially well in New England.
Rhododendron 'Winsome'
The hybrid between 'Humming Bird' × R. giersonianum, forming a very attractive, compact, dense, small evergreen shrub. Some records include: 10 years - 3 x 4 feet; largest on record - 6.5 x 6.5 feet.
The narrow elliptical, pointed leaves, up to 3.7 inches long, are deep green above, creamy-white felted beneath.
The very abundant, rosy-red, funnel-shaped flowers, up to 2.5 inches across, are borne in trusses during spring.
The stems have red winter buds.
Hardy zones 5 to 9, in sun to partial shade. Easy to grow.
Rhododendron 'Yellow Hammer'
An open, upright, medium-sized evergreen shrub that is the hybrid between Rhodo. flavidum & R. sulfureum.
Some records include: 10 years - 6.5 feet; largest on record - 8 x 7 feet.
Easily trimmed and makes a good informal hedge.
The small, narrow elliptical leaves, up to 1 inch in length, are bright green, turning to glossy deep green.
The very abundant, deep yellow, tubular flowers, up to 0.7 inches across, are borne in trusses of 3 during early to mid spring, often repeating in autumn.
Hardy zones 5 to 8, tolerant of full sun.
ADDITIONAL CULTIVARS
https://plantsbymail.com/collections/rhododendrons
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.